Linux

I read that Windows XP has a "new" feature that lets users hot-swap their desktops. Instead of logging out, a user can put his session into the background and another user can log in. This is of course very useful if you are downloading large files or running services and you don't want to interrupt the process. If figured out that Linux is able to do the same already for years:

Connecting from a Macintosh to Linux

OK, it is easier on a Mac. iTunes is free and does it all for you (and does it well). To replace iTunes I need at least three applications on Linux :-(