Have you heard of MUSHing??? It is a text based game, there is a good rping game called Elendor on MUSHing, I'm sure that there are other MUSHing games around. I have only just discovered it myself.....

try www.furcadia.com
you have to create one (or more) avatar and can travel and talk to others in the many worlds and dreams available

absolutly free

and try typing free multiplayer games on google search engine and see how many interesting games you'll get

Ooh yes...Furcada rocks! I used to play on there so frikkin much..I'm a sucker for feral RPs on there, lol...
There's another text-based RPG that's pretty good, Urban Dead. It's like, you can either be a human or a zombie in this city over run with zombies, and you just try to survive...I like it, really realistic. Another thing, if you start as a human, and get killed, you are then a zombie, until you get revived...er...revivified, heh heh... Let's see..there's Kingdom of Loathing...its just a goofy little RPG that makes fun of other RPGs...when I think of more I'll leave them here, I guess.