The most generally useful bit of Star Trek tech has to be the replicators. Need to whip up a meal for unexpected guests? Done. Need a bigger hard drive for your computer? Just say the word. Think a suitcase full of banknotes would come in handy? It can do that too.

Unfortunatly, that didn't appear on the poll, so I had to choose the holodeck. I think we can safely agree that the majority of holodeck users would use it for porn. It would also be great for roleplayers (as Trav pointed out) and for teleconferencing. Heh. You could even have boxing matches where the two competitors are in different countries.

Teleporters would also be cool. The daily commute would be reduced to queueing for your place in the booth. Less congestion and gridlock. Annoying traffic-reporting people would become extinct.

Androids would probably immediatly lead to a new round of religious / ethical debates on the nature of humanity and the soul. But I don't think I would want one for myself - not in case it turned out to be Lore, but in case it turned out to be an Alice*.

Universal translators would allow the French to be able to talk to the rest of us. And I don't think any of us want that, do we?

A cloaking device would be cool, but they're big things. About 4 cubic metres, as I recall. Do you really want to carry that around all day, just to avoid people?

Warp drive would obviously be useful for deep-space exploration, but not much use on Earth. And you couldn't go anywhere that a holodeck couldn't show you. As a species I think we need warp drive, but for myself, I can manage without.

winter"Or a tractor beam. That would be cool, too"mute

*Name the episode and win a fabulous prize.