I used to belong to a MapleStory guild called "JesusRox". I thought it was cool to advertise my faith that way. I eventually was kicked out, (without an explanation, and the only reason I can think of was that the guildmaster wanted to make room for other people).
Now, I'm not too sure it is a great idea anyway. Even though I try to apply my Biblical Morals (kindness, consideration, giving) in the game as well as in life, sometimes my motives are misunderstood and people get upset at me. I don't so much mind them being upset at me, but I don't want my Savior's name to be brought down by it. I realize that the same thing can happen in everyday life, but there you usually have the opportunity to put things into context.
The MS drive-by impressions reminds me of bumper stickers on cars. I also don't put a religious bumper sticker on my car for basically the same reason. I make mistakes, and I don't want my mistakes (cutting someone off, driving too fast, etc) to cause people to think badly of my Savior. Again, say in the workplace where the interactions are longer, you have the opportunity to put things into context, but driving down the highway, you only have one brief chance to make an impression, and its too easy to make a bad one.