...or any way to do it on the OS itself? Since I'm here I might as well ask, and I know it's a common question but for some reason I can't find any of the topics: what are the steps I go through for authorising/using my iPod Touch/iTunes account with a second computer? Thanks
You can create a password protected disk image, which is basically the same thing. http://www.eakes.org/66/password-protect-a-folder-on-the-mac/