What's a good website to find roommate(s) other than Craigslist?

Probably varies by city, might help to provide the location where you're looking.

Baltimore

Have you tried setting up a roommate search as a facebook event, then have friends 'attend' and share the event. The advantage is you are using your networks and (in theory) targeting people who are in a similar stage of life. Someone always knows someone who knows someone who is looking for a room.

http://www.reddit.com/r/baltimore/

There are a fair number of schools in Baltimore; possibly check out the housing websites of other schools too.

Posting on Facebook has gotten a few of my friends good roommates. Also, Reddit is a good option, like theraflu said.

I've seen people place ads for roommates in the http://citypaper.kaango.com/browse/classified-real-estate-rentals/roommates/1162/?distance=3000&latlong=39.290380%2C-76.612190&where=Baltimore%2C+Maryland&search=&sort=date&allmarket=0. I've seen ads both from people wanting roommates and from people looking for rooms.

Nthing the Facebook thing. Adding to what others said: do Facebook and send a mass email to your friends and acquaintances on the east coast, whether or not they live in Baltimore. East coasters tend to bounce around. Boston, Baltimore, DC, NYC, Etc., and everybody seems to know somebody. Make the email easy to forward, and also include a link to the Facebook event. Talk about yourself briefly to paint a picture of how you are as a roommate, list your price range, and preferred neighborhoods. Casting a wide net is your best bet. Does your program at school have a listserv? That might also be a great place to post about it, and would have a different audience than the general school website.