I'm thinking of buying a 500Gb or 1Tb drive to use for both Timemachine backup and to store infrequently accessed music/videos/photos on (since my Macbook only has the 160Gb drive). However, I plugged in another external drive I had lying around with some archived data on it to have a look at how Timemachine works and it wanted to reformat the drive. That suggests I won't be able to use my new drive for both backup and external storage. What if I partitioned the large drive? Can I tell Timemachine to use one partition then use the other partition for my external storage?