New external HDD for use with xp and os x

I bought a WD Mybook 250gb external hard drive and i want to use it for both windows and mac (mostly os x) is there a way i can do this in disk utility without making partitions? I want to be able to read and write on both OS' also i want to use firewire for my MB and usb for my windows machine. Any help would be appreciated. Thanks.

 

thanks, i read somewhere that, that format (Fat32) is not so reliable with a big hard drives is that true??

 

hmm i do have an imovie file or two that are almost 18 gb imovie editing takes alot of space is there any other possible way i can do this?Also what do you mean when you say writing permissions is a drawback?

 

ok so i made a partition so i can transfer large files using journeld format and another using fat32, but why does it only recognize it when the usb is plugged in and not firewire?


ps: never mind its working now thanks for the help.

 

i partitioned it to 50 gb journeld for large files and 200gb fat32 for everything else, should be good no?