Also check out
http://www.comnet.ca/~jkahane/rpg/rpg-definition.html or
http://www.eusa.ed.ac.uk/societies/g...leplaying.html for a definition of the term.
Some role-playing sites that I read are
http://www.gamingoutpost.com/ and
http://www.rpg.net/.
A key difference between roleplaying and wargaming (for example Warhammer 40k) is that with roleplaying there may be no figures and no map. All the action is described verbally (and therefore imagined by each participant).
Cheers
Craig