This is helpful for me because I have several machines that dual boot between Linux and Windows XP, and one that dual boots between OS X and Windows XP. Linux and OS X like to store the time as UTC, while Windows likes to store your local time (e.g. UTC+10). Most Linux distros provide an easy-ish way of storing local time instead of UTC, allowing you to boot into Windows without experiencing a time warp. However, OS X doesn't (to my knowledge) allow this -- which is probably a good thing.
The magic key is at:
It's a DWORD that needs to be set to 1 (I had to create it). Of course, you need to reboot afterwards.
There have been reports of side-effects, but so far it seems OK for me.