Technology proliferation through Diplomacy

[stonewall]

Have you ever noticed that you share a tech with an ally or other civ and then they seem to immediatly share it with everyone else?

One thing I would like to see is the ability to say during diplomacy: "I will give/trade this technology to you only if you promise not to share it with anyone else. If you do then [insert consequence here]"

What do you think?

[Gramphos]

I like it. Maybe also some sort of borrow technologies.
As "I'll borrow you the tools you need to build unit X."
Or "For X gold coins I'll construct a Improvement Y in Z of you cities"

(If they borrow it long they will learn to create them themselves)

[stonewall]

Also, I think I saw this in another thread - when a civ does acquire a technology from another civ (by stealing, trade, etc.) that the civ cannot use it unless they also have the needed prerequisites. For example, in SMAC, I have a faction that acquired a level 3 tech that I didn't have the prereqs for but I was able to utilize the new tech anyway. In Civ, if I am a stoneage civ and I am given the tech that allows flight, my civ would have no concept of what to do with it so why should I get any benefit from it?