I have a 200Gb external drive that I use for video capture and editing via Avid Xpress DV. I've just upgraded from a PB G4 to MBP and, since there's no universal binary version of XDV yet (and it doesn't work under Rosetta), I've just installed the Windows version of it onto my MBP, and so far it seems to work OK. However, I haven't yet tried mounting my external HD while running Windows on the MBP. I'm pretty sure that XP won't be able to read it anyway, but I've been told that XP automatically writes a "signature" to any new HD it detects - could this screw up the drive for when I try and access it again under OS X? And is there any way I could partition the drive so that I have one OS X partition (containing all the stuff that's already on there), and one NTFS partition for use exclusively under XP?