Several users have reported that upon installing the third alpha release of Ubuntu 10.04 Lucid Lynx, their iPod Touches and iPhones are recognised by the operating system. You can browse your iPhone/iPod with the file manager, and Rythmbox can work with them as well.
It appears - please correct me if I'm wrong - that this support comes courtesy of GVFS supporting libiphone, combined with iFuse. iFuse is a FUSE file system driver that connects to your iPod Touch/iPhone through libiphone, using Apple's native AFC protocol (so no ssh or other complicated nonsense). No jailbreaking needed, no patching, no nothing.
It works with music and photos, and support for calendar and contacts is under way - one-way syncing already works through Conduit (import information from your device). Note, however, that you can't just simply drag and drop songs onto the device; Apple uses a proprietary database format (no surprise there) to store song information, so you need to update that too. Sadly, iPhone OS 3.x and higher are not yet officially supported this way, but it is coming.
Hopefully, everything will work by the time the new Ubuntu release is out, and hopefully, other distributions adopt this functionality as well. Of course, Apple will most likely continue its childish act of releasing updates solely to break this functionality, but hopefully the open source community will be able to keep up the pace, narrowing the window between Apple breakage and open source fixage.
Over the weekend, I moved my main desktop over to Linux entirely (erasing Windows), so this functionality couldn't have come at a better time.