Things you want that don't exist.

[JohnT]

Dammit, where's my jetpack!

What do you want that doesn't exist?

[DinoDoc]

Phasers.

[Boris Godunov]

A daily pill that has the effect of a full-body workout.

[Skanky Burns]

Quantum computer.
Teleporter.
Money that grows on trees - preferrably one that directly deposits the money in my bank account.

[monkspider]

Good one Boris.

For me?
Enertron- A device that provides the equivalent of eight hours of sleep in just a few minutes.

[Drake Tungsten]

A yearly pill that has the effect of a full-year of working out.

[Boris Godunov]

Lite beer that actually tastes good.

[Drake Tungsten]

Do you have a body image problem, Boris? You can tell me...

[Boris Godunov]

Would you like to post pics for comparison?

[mrmitchell]

All of these are good suggestions; however, I'd say the teleporter

If I had all of the time that I spent delivering myself to and fro, I'd be able to do the work-outs, get the sleep, make the money, and more.

However, Enertron sounds like a nice substitute if the telporter isn't coming around anytime soon

Drake, how the hell do you expect us to get pills through our medical system?

[Drake Tungsten]

Would you like to post pics for comparison?

No thank you. I don't want Fez to get ahold of a pic of me, thank you very much...

[Shadowstrike]

Computer Gaming Time Warp - no matter how long you play, only a few seconds have passed.

Same with Forum Surfing Time Warp.

[Bereta_Eder]

Teleporter, definitely

[mrmitchell]

Shadowstrike--excellent ideas.

Actually, I'd like Time Warps for Sleeping too.

[monkspider]

Imagine how revolutionary it would be if something like the Enertron were created. We spend about a third of our day sleeping usually. People would have unprecedented free time to learn new things and so forth.
I would probably still sleep every once in a while though since it's something I enjoy.