I've tried updating my iPhone to iOS5, but iTunes is telling me that I don't have enough space to backup my phone. Apparently I need almost 27 GB (most of that being apps), and there's no way I can make that much room on the computer. Otherwise, if I chose to continue anyway, it would "result in a loss of all media". I don't have a lot of music or photos that I desperately need backed up, but I'd rather not lose them. Plus, I have a lot of apps that I don't want to lose. Would it be possible to back everything up to an external drive for the update?