There are lots of things you could do. You could drink around the world showcase at Epcot-- Start in Mexico with Margaritas or Dos Equis, and make your way to Canada, stopping for a beer in UK, US, Japan - etc. You could have dinner, maybe at Big River Grille at the Boardwalk (it's a brew pub) then go to Pleasure Island, if you aren't into dancing you could go to the Adventurer's Club (monty python-esque) or the Comedy Warehouse (stand up comedy) or the new Raglan Road (bar and restuarant) You could go to the dueling piano bar Jellyrolls at the boardwalk. You could go to the Atlantic Dance Hall, which I think is now a Jazz club. You could go play a round of golf or minigolf and make a day of it. You could go to DisneyQuest and play video games

You could sign up for one of the tours that Disney offers, like the Segway tour.. (Segway's are the personalized standup people movers)
I don't know as much about outside Disney -- but I know that they have lots of dinner shows, like Medieval Times -- I think there is a City Walk at Universal (which is probably like Pleasure Island)
As for Groomsmen gifts.. it depends, do you want to give everyone the same thing? or something personalized for each person? My guy was a groomsmen for a friend last month, and each person got a different gift, he got a personalized yo-yo (he has a small collection) another guy got a flask cigar holder combo, another guy got a personalized beer stein. It kind of depends on the guys too.. you could give them all cuff links they could wear at the wedding.
Just some ideas!
--heather