I didn't see this posted yet so here goes.
Insect raven has added FM radio support to a 35 kernel. You have to be using a Rom with sense UI as the only known app requires this framework.
It appears to be stable and I am planning to test in a few days.
[Kernel] [.35-rcX]intersectRaven's Kernel (FM SUPPORT!!!)07/15/2010 03:12pm - xda-developers