Cabaret magic acts are great fun, and don't require much space. These are the acts in which the magician might display escape tricks, saw someone in half, or make their assistant disappear -- all the classic tricks that people tend to expect.
Small magic shows lend themselves to combination with comedy and music, and are great venues for audience participation. If you'd like to take this route, be sure that you and the magician coordinate with the other acts well before the actual performance.