Not wanting to be tangential but is exFAT any good? And what do others use for a cross platform file system? I sadly had to format a portable 600GB drive as FAT32 the other day, just so it would play ball across OSs and devices. I went to use extFAT, then realised I'd have to use FUSE to get it to work so fell back to FAT32.

Also is it backwards compatible with the other FATS; as in can't you read an ext4 as ext3 (hoping that I haven't made that up)?