Game Informer (owned by GameStop) this weekend announced that more than 3,300 GameStop locations in North America have demonstration units of the PS Vita available for people to come by and play. I'd advise calling first to see if your local store is letting it out for everyone to handle.
[Update: Monday, 10:44 p.m.] The GameStop in question told Kotaku that its store policy is to show a PS Vita to anyone who asks to see it, regardless of preorder status. The sales associate quoted below was mistaken, the store says. The original post follows.
As 3,300 is a huge figure (it's basically half the company's worldwide locations) I figured that means most every store in the U.S. has a PS Vita. I called one of the two GameStops local to me to check. They indeed have a demo unit but they're only showing it to people who have pre-ordered the PS Vita.
That's per the district manager, I was told, so I can't say that's a nationwide thing. It sounds like the one my local store has isn't attached to a kiosk, so taking it out, showing it to a customer and supervising his use of it can be a time-intensive thing they only want to do for someone who's committed to buying it.
Bottom line, call and confirm its playability before you head over. If it is playable at your store, great. Among the games you may be able to try are: Uncharted: Golden Abyss; Little Deviants; Hot Shots Golf: World Invitational; EA Sports FIFA Soccer; ModNation Racers: Road Trip; Virtua Tennis 4: World Tour Edition; Escape Plan and wipEout 2048.
The PlayStation Vita launches in North America on Feb. 22.
Update: We've called several other GameStop stores around the country and they're offering the demonstration units to everybody.