The problem with multi-function devices is that there are contradictory requirements. I want a book-reader that's pretty much the size of a paper-back book, because a large screen is comfortable to read on. I don't
want a mobile phone that's the size of a paper-back book
I've combined most
of my device requirements into my "HTC Touch" Windows Mobile Pocket PC/Mobile phone. This is about the size of a pack of playing cards and is, for me, pretty much the ideal size for a PDA/phone. That's what I use as a phone, for my diary, address book, notebook, and a million other things. It will
work as a bookreader (I have MobiPocket Reader installed on it) but, as I said above, I want to read on a larger screen.
The perfect device for me would be something the size of the HTC Touch, but with a "roll-out" screen for reading on. Perhaps that will arrive in a couple of years.