Does your state have a DMV? In VA you can go to their site, and preview plates. It will also tell you if its available.
Funny timing with your post, I just left the MSN funny plate article:
Number 11 cracked me up
06 330i 6mt Spt- Eibach Springs, BMW Perf Susp, Supersprint Exhaust, BSW Audio
94 325i 5mt 4d- M3 springs/susp, Z3 wheels, Chipped, Intake, Exhaust= FUN!