Medical Technology
On Star Trek, the doctors have handheld devices that instantly close any openings in the skin. Imagine that sort of device in the hands of your unscrupulous friends. They would sneak up behind you and seal your ass shut as a practical joke. The devices would be sold in novelty stores instead of medical outlets. All things considered, I'm happy that it's not easy to close other people's orifices.

Transporter
It would be great to be able to beam your molecules across space and then reassemble them. The only problem is that you have to trust your co-worker to operate the transporter. These are the same people who won't add paper to the photocopier or make a new pot of coffee after taking the last drop. I don't think they'll be double-checking the transporter coordinates. They'll be accidentally beaming people into walls, pets, and furniture. People will spend all their time apologizing for having inanimate objects protruding from parts of their bodies. "Pay no attention to the knickknacks; I got beamed into a hutch yesterday."

If I could beam things from one place to another, I'd never leave the house. I'd sit in a big comfy chair and just start beaming groceries, stereo equipment, cheerleaders, and anything else I wanted right into my house. I'm fairly certain I would abuse this power. If anybody came to arrest me, I'd beam them into space. If I wanted some paintings for my walls, I'd beam the contents of the Louvre over to my place, pick out the good stuff, and beam the rest into my neighbor's garage.

If I were watching the news on television and didn't like what I heard, I would beam the anchorman into my living room during the commercial break, give him a vicious wedgie, and beam him back before anybody noticed. I'd never worry about 'keeping up with the Joneses,' because as soon as they got something nice, it would disappear right out of their hands. My neighbors would have to use milk crates for furniture. And that's only after I had all the milk crates I would ever need for the rest of my life. There's only one thing that could keep me from spending all my time wreaking havoc with the transporter: the holodeck.

Holodeck
For those of you who only watched the 'old' Star Trek, the holodeck can create simulated worlds that look and feel just like the real thing. The characters on Star Trek use the holodeck for recreation during breaks from work. This is somewhat unrealistic. If I had a holodeck, I'd close the door and never come out until I died of exhaustion. It would be hard to convince me I should be anywhere but in the holodeck, getting my oil massage from Cindy Crawford and her simulated twin sister. Holodecks would be very addicting. If there weren't enough holodecks to go around, I'd get the names of all the people who had reservations ahead of me and beam them into concrete walls. I'd feel tense about it, but that's exactly why I'd need a massage. I'm afraid the holodeck will be society's last invention.

Sex with Aliens
According to Star Trek, there are many alien races populated with creatures who would like to have sex with humans. This would open up a lot of anatomical possibilities, but imagine the confusion. It's hard enough to have sex with human beings, much less humanoids. One wrong move and you're suddenly transported naked to the Gamma Quadrant to stand trial for who-knows-what. This could only add to performance anxiety. You would never be quite sure what moves would be sensual and what moves would be a galactic-sized mistake.

Me Trying to Have Sex with an Alien:

Me: May I touch that?
Alien: That is not an erogenous zone. It is a separate corporeal being that has been attached to my body for six hundred years.
Me: It's cute. I wonder if it would let me have sex with it.
Alien: That's exactly what I said six hundred years ago.

The best part about having sex with aliens, according to the Star Trek model, is that the alien always dies a tragic death soon afterward. I don't have to tell you how many problems that would solve. Realistically, the future won't be that convenient.

Phasers
I would love to have a device that would stun people into unconsciousness without killing them. I would use it ten times a day. If I got bad service at the convenience store, I'd zap the clerk. If somebody with big hair sat in front of me at the theater, zap! On Star Trek, there are no penalties for stunning people with phasers. It happens all the time. All you have to do is claim you were possessed by an alien entity. Apparently, that is viewed as a credible defense in the Star Trek future. Imagine real criminals in a world where the 'alien possession' defense is credible.

Criminal: Yes, officer, I did steal that vehicle, and I did kill the occupants, but I was possessed by an evil alien entity.
Officer: Well, okay. Move along.

I wish I had a phaser right now. My neighbor's dog likes to stand under my bedroom window on the other side of the fence and bark for hours at a time. My neighbor has employed the bold defense that he believes it might be another neighbor's dog, despite the fact that I am standing there looking at him barking only twenty feet away. In a situation like this, a phaser is really the best approach. I could squeeze off a clean shot through the willow tree. A phaser doesn't make much noise, so it wouldn't disturb anyone. Then the unhappy little dog and I could both get some sleep. If the neighbor complains, I'll explain that the phaser was fired by the other neighbor's dog, a known troublemaker who is said to be invisible. And if that doesn't work, a photon torpedo is clearly indicated.

Shields
I wish I had an invisible force field. I'd use it all the time, especially around people who spit when they talk or get too close to my personal space. In fact, I'd probably need a shield quite a bit if I also had a phaser to play with. I wouldn't need a big shield system like the one they use to protect the Enterprise, maybe just a belt-clip device for personal use. I could insult dangerous people without fear of retribution. Whatever crumbs of personality I now have would be completely unnecessary in the future. On the plus side, it would make shopping much more fun.

Shopping with Shields Up:

Me: Ring this up for me, you unpleasant cretin.
Saleswoman: I oughta slug you!
Me: Try it. My shields are up.
Saleswoman: Damn!
Me: There's nothing you can do to harm me.
Saleswoman: I guess you're right. Would you like to open a charge account? Our interest rates are very reasonable.
Me: Nice try.

Long-Range Sensors
If people had long-range sensors, they would rarely use them to scan for new signs of life. I think they would use them to avoid work. You could run a continuous scan for your boss and then quickly transport yourself out of the area when he came near. If your manager died in his office, you would know minutes before the authorities discovered him, and that means extra break time.