This can be a good idea depending on what kind of job you are looking for, what kind of community you are part of and what your role there has been. If you are applying for a job flipping burgers and your role has been VIP MEMBER on CobraKatana99's Street Fighter Dojo then maybe it is not such a good idea, but if you are running a successful community of some type and are applying for a web-related job then it could be a good way to convey your management and organizational skills as well as your web, internet and community know-how.
I think Bart put GW on his CV, and I recall a few people I know IRL having done similar things as well.
It is relevant I guess.