Instead of challenging each other, why don't we just look at the numbers?
Intel HD Graphics 3000
NVIDIA GeForce 320M
Type - HD3000 - 320M
3DMark03 - 11406.5 - 10494
3DMark05 - 8695.8 - 7168.3
3DMark06 - 5053 - 4346.5
SC2 (Med. Avg.) - 21fps - 26fps
DIRT 2 (Med. Avg.) - 29fps - 28fps
Left 4 Dead (High Avg.) - 65fps - 47fps
There are many more tests in the links, but it seems that in benchmarks the HD3000 seems to win, but in real-world tests it's very hit-or-miss.
This was pertaining to the 2600 in comparison to the 3000. The 320M had nothing to do with it.
ATI 2600 - Intel 3000
3D Mark 06 | 3133 - 5053