A limousine is a great way to get around town to all the hot spots. And you and your crew can have more fun drinking if you have a "designated driver".
Besides, limos are cool.
Talk to your friends and see if any of them know of a good limousine company. Chances are one of them will. Call and talk to the limo company to hear exactly what they offer.
Size does matter, if you have too many for one limo (they usually can seat six to twelve passengers) you may need a couple cars. It's important that the two drivers know exactly where they are going and communicate as they drive, (you don't want them heading to different clubs).
Amenities are nice, AM/FM cassette, television with VCR (tapes, don't forget the tapes), drinks anyone? Ask them what they offer.
Do you have the vehicle for the whole evening? Or is there a time limit?