PS3/360 Owners, What Makes You Switch From One Console To The Other?

Are you a gamer who is fortunate to have both an Xbox 360 and a PlayStation 3?

Do you find yourself getting in a groove with one machine and ignoring the other? If that's the case, I was wondering what makes you switch? Or are you constantly hopping from one machine to the other?

I ask because I noticed that I had been playing 360 for several weeks this winter, choosing against the PS3 versions of multi-platform games, because I have more friends on Live. Then the noise of the Xbox started getting to me and I switched to the PS3, which, thanks to "Burnout Paradise," is now linked to a lot of my friends, too. I think "GTA" will yank me back to the 360.