$350-ish. NO DRM! Linux-based. Supports eBooks in HTML, PDF, RTF, and MobiPocket PRC formats. Takes SD cards for storing your library, above and beyond the memory that comes in the system. Want one?
N.A.E.B. (Not Another E-Book), LLC, has put together a deal with Bookeen to make it possible. If they get sufficient interest for the minimum bulk order (300 people, I think), the price is as stated. If they can get 1,000 sales, the price goes down. Specifications are at http://www.naebllc.com/page4.html and you can sign up - which is an expression of interest, not a commitment to buy - at http://www.naebllc.com/page3.html. Go, sign up, spread the word!
IMO, something like this is not as convenient as my PDA - there's no backlight on this reader, and it's about the size of a paperback book, rather than a large cellphone or a Palm or Pocket PC, but in good light, the display quality is expected to be superior, and easier on the eyes than most PDA fonts. If quality is more important than size, this is the way to go - I know that my father has switched from reading on a PDA to reading on the Sony ebook reader, and I'm pretty certain it's because the Sony is easier to read for aging eyes.
(The people that are doing this haven't actually taken up the idea, but I think of the reader as NAEBR (Not Another E-Book Reader), pronounced "neighbor", and anyplace that you can get ebooks that can be read on the NAEBR is obviously part of the NAEBR-hood. Compatible formats, and the people who make their ebooks available in them, are NAEBR-ly.)