Assuming it's not a heavyweight dance club, and you can rely on the DJ's co-operation (an advance phone call will smooth the way), why not try something like a quick line-dance competition? Nominate one of your party as judge, all take cowboy hats, and wear them while the DJ plays a Shania Twain single, or Rednex, or something similar, and do your thang - takes three minutes, it's a good laugh, and it won't look like you're trying to take over everyone else's evening. Have fun.