Playing CoD: Modern Warfare on a Macbook Pro 13" (Mid-2009) I have a mid-2009 MBP (13"/ 2.53Gzh/ 8GB). I installed Call of Duty: Modern Warfare on it at the weekend only to find the on-board GPU can't cope with it.

I'd like to do a bit of gaming on it, but am concerned that modern titles are going to be too much for it. Can anyone suggests workarounds to let me game on my otherwise lovely laptop?
OnLive actually works surprisingly well on those little MBPs, I was using it for a while as I'm not a particularly hardcore gamer so don't mind the graphics not looking amazing.