We did this at my job (MDACC) a few years back. I believe the beneficiary was the United Way, but don't quote me on that.
In addition, the "prisoners" had to use their "one phone call" to get someone to post bail.
We had actual UT police and I think some HPDs and Harris Co Sherriffs do the arresting, to really add to the ambiance.
My boss at the time (MD/PhD in the lab) was a total ogre, so we were cartwheeling when he got his! Fun way to needle someone being a PITA and raise money for a good cause.
If you can get your paperwork thru your Student Activities Office (or whatever you call it) I would recommend this highly!
Adrienne (PNAM-2003)
(Edited to add--I know this is an old thread, but the idea is so good it deserves a bump!!)