Hi Guys, Basically I know nothing about Apple's format and FAT32, NTFS, etc. stuffs like that. So your helps will be highly appreciated. I want to purchase an external HD recently to use it as a Time Machine backup drive. Meanwhile, I also want to use it as a PC/MAC compatible drive to transfer files between PC and my macbook. The question is, what type of format can achieve my goal? Do I need to divid the HD into 2, one for TM one for storing files, and format them into 2 different formats? The new version Seagate FreeAgent is my favourite, and it provides a special "for mac" version which the format of Time Machine has already been built in, however it costs much more then the normal version, is it worth to buy such a "for mac" version despite the high price? There're so much I dunno hence the long question list, sorry for the hassle and thanks again for your posts.