I got my hands on a 2.4GHz MacBook 13" 'late 2008.' Since its native resolution is 1280x800, I ran five 3D game benchmarks at that resolution so I could compare it to the 2.53GHz and 2.8GHz MacBook Pros. As you might expect, the MBPs blow it away. But it's not as pathetic as the MB with the GMA X3100 or 950.
http://www.barefeats.com/mbpp05.html
http://www.barefeats.com/mbpp05.html