Looking for a change of mobile OS? Have a look at Ubuntu 9.04, a brand new operating system for Nokia N8x0 tablets that has just recently become available. Ubuntu 9.04, also known as Jaunty Jackalope is compatible with N8x0 devices, including Nokia N800 and N810.
You should know that the OS doesn’t support audio and Usplash, but every other feature works just fine. Check out this adress for a guide on how to install Ubuntu on your handheld.