Ok, tried it out, pretty good guys. Takes 20mins for a 20GB HD with about %35 fragmentation (rofl, backing up scratched dvd's is teh ghey).
Now, for kicks I tried defragmenting while playing a game. I was playing HL2 while defragging the 2nd hd which the game was installed on. VERY impressed hea, cpu usage was about %10 with diskeeper and winamp and firefox, so with the game I was still getting great framerates! being able to defrag while pwning it up definately puts this high on my list folks. It's definately the best defragging program for us gamers. I'll see if I can pay me sis $30 to use her credit card to order the full thing.
So yes people, this program is worth the cash I say. Works with ntfs and fat* drives, so it should work great in windows longhorn.