Nokia recently announced its Linux-based N810 tablet, and although the device is not yet widely available, the accompanying software is. The new operating system, designated Internet Tablet OS2008, is available as a free download for owners of the previous N800 model. In that rarest of all outcomes, the new release actually improves the older tablet -- it is faster, improves battery life, and should make it easier for developers to port applications over from desktop Linux.
The IT OS2008 download is currently marked a beta release -- a situation not likely to change before the official release of the N810. It is a 128MB binary firmware file, up in size significantly from the 90MB of IT OS2007. To download it, you must have an N800 tablet, as the site requires authentication of your tablet's WLAN MAC address, which is printed on the identification sticker inside the battery compartment.