Clever Linux developers have figured out how to install a working copy of WikiPedia on an iPod.
Installing the portable reference guide requires that Linux be installed on the iPod first. The developers direct interested users to install iPodLinux, though doing so may void Apple's warranty if you use a new iPod.
Once that hurdle's crossed - there's another - users must then install and delete files held on the iPod.
With that hurdle overcome, users can install a variety of different language versions of WikiPedia on their iPod, and also install and read a variety of eBooks which are made available online.