Question : Problem: How to set up single external hard drive to work in MAC and PC?

I just bought a Seagate 200 GB external hard drive which I plan to use on a MAC for digital video storage, but I would also like to use it with my PC at home to back up my files, for games, and for additional storage.  I know I can partition the hard drive for whatever size I need each to be, but the question is what should the hard drive file system be formatted to in each the PC partition and the MAC partition, NTFS or FAT32, or does the drive need to be partitioned at all?  The OS for the PC is XP Pro and for the MAC is OS X.

Answer : Problem: How to set up single external hard drive to work in MAC and PC?

I setup a 30GB external hard drive for my girlfriend.  She needs it to scan her pictures and slides at school on a MAC.  I plugged in the hard drive on my XP PC and formatted it in FAT32 format.  Then, she uses it on the MAC at school and bring home her files and edits them in Photoshop on a XP PC.  It works fine and great.  The only thing she told me was that you had to eject(?) your external hard drive in MAC before disconnecting it, otherwise you may lose some data.  

AS STATED FROM A WEBSITE:
If it is possible to remove a device physically without ejecting it, (for example, unplugging a firewire hard drive or USB pen drive) -DON'T Always eject the device first, unplugging active devices can lead to corruption or loss of data.