I went to Las Vegas with friends a few years ago, and one of the things we did was to check out Star Trek: The Experience at the Vegas Hilton. It's expensive, but you can walk through a museum which has props from the shows and a timeline of the Star Trek universe, there's a bar modeled after Quark's in DS9, and there are two rides: The Borg Invation 4D and Klingon Encounter. I actually didn't much care for the Borg show, the the Klingon ride was pretty cool. Walking through the museum was fun, and Quark's was a kick. There's also a good gift shop that'll be happy to overcharge you for souvenirs.
Looks like they may be shutting the thing down. So if you're in Vegas before September, and if you like Star Trek (and are OK with throwing away some cash), go check it out while you still can.