ebook reading really seems to be the killer application for tablets and/or big-screen PDAs (if there is a difference between them besides the lack of PIM tools). InternetTabletTalk [1, 2] amongst many seem to think this way. Also yesterday at a friends birthday party (90% IT workers aka GEEKs) we had a short discussion about PDAs, portable media players and friends. Many of us came to the conclusion that we want a viewing devices. This means mainly: PDFs, HTML and insert popular ebook format here. Everybody complained about their favorite device either the screen is to small or unreadable outside, the device is too slow when rendering content, storage is to limited or DRM sucks to badly. Also what about watching movies on the same device? Na - we don't want that, that just makes the device to multi purpose and that never works out well.
As a comment to Russell's review, I really think Internet access is the killer application for the Nokia 770. All the other features are just add-ons. Of course you need the special viewers (web browser, rss reader, audio streaming client and all the different format readers).
Finally what I would like to know is, if people carry around their 770 during the day (when you are not at home/office)? Are you carrying it around with your cellphone or do you keep it at home close to your couch and fast wifi access? I personal only take it to places where I know wifi is available for me.