I'm not sure if this is the best place to ask, but here goes... I just bought a new iMac with the smaller hard drive since I know I can add more storage through external drives. Right now I have connected two external drives. One drive is OSX formatted and the other is NTFS for my Windows junk. So my question is: If you had a single external HD, say 500gb, can you set it up so that half the drive is one partition formatted for OSX and the other half NTFS for Windows?