I learned here that my old Nokia N800 Internet Tablet could be used as a most excellent reader. Now I read more on it than I do on either my Sony PRS-505 or my jetBook.
Is an N800 a full fledged computer? There are those who would say yes, and it is more powerful than the first several computers I owned. Although, one of the reasons I like it is it fits quite nicely in my pocket, unlike any netbook or UMPC I've ever heard of.