Not really. It's possible to get the video working, but iSight's audio is, as yet, not supported in any way. (Contrary to what you will find on some sites if you google it, the iSight is NOT a DV camera: it's IIDC. Windows supports IIDC, but the iSight image will not be properly exposed, so you'll have to find a program that lets you adjust the picture.)
The other thing is that most PC laptops (and many desktops) have only a 4-pin FireWire port, not 6-pin. 4-pin doesn't carry power, and thus the iSight can't work on those with a plug adapter. You'd need to use a powered FireWire hub in such a case.
tooki