Let's try this again. Here's the summary for the last thread.
WORLD'S GREATEST: Ecce Homo
By paying double the shield cost, a civilization can build a World's Greatest city improvement, which grants a small bonus for that city (double effect, as in +100% gold for marketplaces, 4 citizens happy for temples, etc.) Another civilization can pay double that to outdo the current World's Greatest. A temple = 20 shields, the first World's Greatest = 40, someone else spends 80 to outdo them, etc.
Pythagoras: Suggests limited timespan for world's greatest.
kmj: Suggests "bidding" for world's greatest. Suggests world's greatest can go obsolete, i.e. World's Greatest Marketplace loses all bonuses upon discovery of Banking.
Glacier: World's tallest building or longest bridge/tunnel could provide extra gold or happiness.
PROGRAMMABLE WONDERS: EnochF
A long series of flags allows players to redefine current wonders and create new ones to a much larger extent. Any Wonders dropped from the final release of the game might still persist as possible game effects to be used by scenario and modpack designers.
WONDER DETERRENTS: Ufa
Random negative effects for more powerful wonders. Leonardo's might leave a percentage of units not upgraded. Lighthouse has a chance to burn out each turn.
EnochF: As an alternative to random effects, use constant negative effects instead. Increased pollution or corruption in the host city, slight happiness reduction for the civ, high maintenance cost in gold, or something along those lines.
WONDERS OFF OPTION: kmj
An option in the game menu to disallow all wonder effects (and even the ability to build wonders). Alternatively, an option to "tone down" wonders, maybe decrease effects by half wherever possible.
Ufa: A "modifier" for wonders, like Civ II's modifier for barbarians
Mark_Everson: Disallow wonders that count as an improvement in every city. Wonders that never go obsolete are unbalancing.
Ecce Homo: Suggests Pyramid be city improvement, thus Great Pyramid = world's greatest
DISALLOWING "RACES TO BUILD": meowser
No two cities in one civilization can build the same wonder at the same time.
CyberShy: No races allowed at all.
kmj: Races between two civilizations should be discouraged but not disallowed by the game. A message appears, such as, "Sir, the Egyptians are believed to be working on a similar project. Shall we continue?"
SnowFire: Disallowing switching production would severely handicap the AI. A player can always buy the wonder at the last minute, leaving the computer with a great deal of wasted production.
ErikNYC: Left-over production could be converted into trade, food, science, or some other variable related to the Wonder being constructed.
EVOLVING WONDERS THROUGH THE AGES: Eggman
Wonder effects which change as the ages progress. Pyramids act as granary early on, then change to gold bonus. Olympic Games provide extra gold, cease to function in Renaissance, then increase happiness in later ages, etc. Aging wonders may incur higher and higher maintenance costs.
EnochF: All obsolete wonders generate tourism gold.
SnowFire: Aging wonders should not incur maintenance costs simply because they are obsolete. However, maintenance costs for certain Wonders may be feasible.
EdCase: When a Wonder goes obsolete, adds 10% to income of the city.
Depp: The game's more fun when Wonders never go obsolete.
LAND ENGINEERING WONDERS: Diodorus
The Great Canal, for example, requiring explosives, modern engineers, allows trade routes. The Polders may reclaim land from the sea. A Great Wall which actually acts as a physical wall along the civ's borders.
Ecce Homo: Canals, bridges, walls could be city improvements. The World's Greatest Canal could have effects resembling Great Canal.
kmj: Land engineering Wonders are limited by the surrounding terrain, no Great Canal by water
RE-BUILDABLE WONDERS: meowser
Only if two rival civs are building the same wonder, the second civ to complete the wonder receives a "compensation" bonus of happiness or gold. The first civ receives the standard wonder effect.
Fugi the Great: Civs can build the same Wonder and call it something different.
NATURAL WONDERS: CyberShy
Effects are conferred upon a civilization simply by having the wonder in its territory.
Taedott: Natural wonders are a resource, no benefits unless "improved."
meowser: Natural wonders appear on Earth map, or randomized on map like SMAC geographical features. Size: 1 tile, offer resource bonus, can be "improved" to provide tourism.
VISIBLE WONDERS: EnochF
Certain Wonders would appear in the city radius as impressive graphics. They would not confer any bonus to the worker on that square.
meowser: Visible wonders should be vulnerable to pillage (without direct assault on the city).
Ecce Homo: All Wonders should be visible. If it's not visible, it's not a Wonder (Women's Suffrage, Internet, Emancipation Act are thus disallowed)
"CULTURE" PARTLY DEFINED BY WONDERS: Trachmyr
Part of a larger system suggested in other forums. The Wonders a player builds help define a new game element called "culture," which may affect a civilization's war readiness, science, economy, government, even graphical representation on screen. A fairly radical reordering of traditional Civ. Bears resemblance to "social engineering" as found in SMAC.
Darkstarr: Special Projects could be mechanisms for adjusting social engineering.
CULTURAL WONDERS: meowser
Certain Wonders are only constructible by certain civs. Which civ can build which Wonder may be randomized at the beginning of the game.
kmj: Disagrees with cultural wonders, warns against "factions" rather than civilizations.
UNCERTAINTY OF WONDER EFFECTS: CyberShy
Effects of wonders should not be predefined. Effects of the Wonder should only become clear to the builder X number of years after it is built.
GRADUAL WONDER OBSOLESCENCE: Zorloc
Wonders should not cease all effects on obsolescence, but gradually "phase out" over a few turns.
Zakalwe: Suggests something similar for captured wonders. Effects do not take effect immediately.
COOPERATIVE WONDER BUILDING: meowser
Certain limited Wonders could be jointly built by a conglomeration of nations. United Nations is an obvious choice.
SHARED WONDERS EFFECTS IN ALLIANCE: meowser
Also suggested in the Diplomacy list. All civs allied with each other receive the effects of each other's Wonders.
WONDER CATEGORIES: Ecce Homo
Certain Wonders are not dependent upon shields (resources) to be built. Scientific Wonders built by beakers, Economic Wonders built by gold.
WONDERS WITH UNIVERSAL BENEFITS: Ecce Homo
Growing out of Sieve Too's Internet Wonder. Many wonders provide benefits to all civs, i.e. the Olympic Games open to all who choose to participate, Wormhole Sensor, Apollo, Manhattan, etc.
willko: Disagrees. Wonders should have localizable benefits to the city they are built in (e.g., Lighthouse only functions at X distance maximum). Any wonder with a "universal" benefit should have a separate "non-universal" benefit, i.e. Manhattan Project also grants +25% science.
WONDERS AS A CIVILIZATION-WIDE PROJECT: meowser
Wonders are not built on the level of the city at all. Instead of being a city project, they are built by the entire civilization, using X% of total production or some such thing. Wonders thus do not appear in cities but in a special "wonder screen."
Fugi the Great: Wonders built by engineers or terraformers rather than X% of production. Increase costs of Wonders.
NAME YOUR OWN WONDER: kmj
Hoover Dam may be called Aswan or Three Gorges or London Dam. Forbidden City may be called Imperial Palace, Throne Hall of Persepolis, Palace of Versailles or Atlanta Palace. The Agency may be called FBI, CIA, KGB, KLA or KMJ Killer Squad.
Trachmyr: The game should suggest a few key names.
LANDSCAPE LIMITED WONDERS: kmj
Lighthouse only in coastal city, Hoover Dam requires a river. Only applies to certain Wonders.
SMALL WONDERS: willko
Suggests a huge number of wonders (rather than Wonders) with small effects, usually increased trade. Examples: Space Needle, Leaning Tower, etc. Rather than huge Wonders with sweeping effects like Pyramids, have countless small wonders with tiny, localized effects.
INTERNET WONDER: Sieve Too
A suggestion that provoked a huge response of support. The Internet wonder would provide benefits to not only the host civilization, but all civilizations with the Computers advance. Sparked the discussion about "universal" wonders.
anachron: Internet should be a technological advance, not a Wonder.
HUMAN GENOME PROJECT: anachron
Should have military ramifications, such as the ability to infect an enemy city with genetically engineered virus and start an epidemic.
SEVEN WONDERS PER AGE: mrtemba
Every age should have exactly seven Wonders.
SPECIAL PROJECTS: Darkstarr
"National Special Projects" is the general category, of which Wonders are a subset. Wonders are unique NSP's, but certain NSP's would be rebuildable. Certain Wonders could enable the construction of other NSP's.
DELAYED AVAILABILITY: Ufa
Merely having researched the appropriate technology does not immediately allow the construction of the Wonder associated with that technology. There is a cumulative chance each turn that someone will "think up" the Wonder, making it available for your civ to build.
Next up, the complete list of Suggested Wonders.