Remember the "Ubuntu 10.04 supports iPhone / iPod Touch out of the box" article? It was actually libimobiledevice (and usbmuxd/gtkpod) who made this possible, not Ubuntu.
libimobiledevice (formerly known as libiphone) development started in 2007 and today it hits the first stable version: 1.0.0 and was followed by the release of usbmuxd 1.0.3. The result is that now you can say that in fact "Linux supports iPhone / iPod Touch out of the box!". Most distributions will feature the library in their next release. For now, the following have confirmed using libimobiledevice: Ubuntu Lucid, Fedora 13, openSUSE 11.3 and Mandriva 2010.1.