I'm dual booting between Win7 and Ubuntu 8.10. Is there anything special I need to do to share a drive between the two? Or since they're on different file systems you cannot? For example a partition that holds mp3s.
One other option is to use a driver like Ext2 IFS For Windows to make Windows read/write the file system your Ubuntu runs on (should be ext2 or ext3).
I have used this approach with Windows XP and Ubuntu 8.10 & 9.04 successfully. I had my Thunderbird profile stored on the Ubuntu drive and could therefore access it from Windows and Linux off of the ext2 partition. With the driver the Linux drive is then simply accessible from Explorer like a FAT32/NTFS disk.
I never had any problems with this, but you might want to check out the website for potential issues.
The easiest thing to do is probably to devote a partition formatted as FAT32 to the files you want shared.
Linux can read NTFS drives, though, I just wouldn't recommend writing too much. Iirc even the FuseFS NTFS driver disables writing after a certain amount to avoid clobbering too much of the file system that it can't repair itself anymore.
So if you want both systems to write on that partition I'd recommend a separate FAT32 partition, if you need only read access from Linux then just store everything on NTFS.
FAT32 is the usual, to have a shared partition (can be written/read under Ubuntu and Win7). Though Ubuntu can read (and maybe write ? Not sure) on NTFS partition. So in general, a shared partition will be easier if formatted in FAT32. Though be careful of limitations, you won't be able to have a file with a size superior to 4gb on it. (but I guess that for mp3 it will be ok ;) )
For the opposite (reading pure linux partition (ext3, for example)), you will need software like explore2fs