A fantastic, very open-ended, and extremely well-populated online RPG is a MUSH (Multi-User... something-something...) called Shangrila. You need some sort of client to run the program, but a lot of quality people play there, and they're really helpful. I think the website is shangrilamush.org, but I might be wrong... it's been a while since I've been there. You can toss any manner of character into this dreamland setting (or nightmare, depending upon your role!) and meet a lot of great people. I will warn that most people are pretty into the writing, but considering how many of you write anyway, that shouldn't be a problem for anyone who wants to check it out. As for clients, try something like zmud or mushclient. (A google search on either one will take you straight to their respective websites... I'm lazy.)