I act a bit different in game than I do on the forum.
For the most part, I'm far more active in game than I am on the forum, and of course my real personality differs from that of the main character I play in the game. I'm always out of character on the forum, since I don't really roleplay on here. I'll be viewing this question from when I'm out of character.~
On the game, I'm very vocal. I love striking up conversations and just having a good time with every player around me. The character I frequently play, Lament, comes off as a vivacious, flirtatious, and smugly hyper fellow. It certainly rubs off into my personality on there, often referring to others by pet names and having no boundaries when it comes to personal space. Though, it's all in good fun and I don't mean to offend anyone. Also, if you were to see my behavior in group, you'd probably think I was some immature and suggestive maniac. That, however, is just how I act around my good friends and main pack!
On the forum, I try to be a bit more professional, but come off just as friendly, since I see no benefits in being negative or shy. I certainly do tone myself down on here and I'm not as crazy as I am in game. ^^;