This is really preliminary stuff at the moment, but it looks like you will soon be able to run a version of Linux on the iPhone 4, iPod touch 4G, and iPad. You might even get it on the iPad 2, but for now, the image shows Linux booting up on a first-gen iTablet. This could also pave the way for the Google Android operating system to work on newer iDevices too.
The tablet, get this, ships without an OS pre-installed. It’s totally up to you what operating system you want to load onto the beast, assuming that it is compatible with the hardware found inside. According to the devs, the internals should be good for “almost any OS,” including Linux, Windows, and even OS X.