I have a Windows desktop (running Win7 64 bit) and a recent MacBook Pro (running OSX 10.7 Lion). I am looking at getting an external hard drive for backup purposes. As I understand it, the two use different file systems which don't interoperate. Is it possible to work around this, perhaps by partitioning the external drive? I don't mind if they can't write to the file system they don't use (although being able to read would be nice) but keeping it all on one physical disc would be great.