Another interesting product out is the T-Mobile [danger] Sidekick2.. its a phone/pda.. I ended up getting it for free on amazon.com after rebates, and on top of my regular phone plan, I only pay 20/mo for unlimited data and its pretty fast. It offers a browser, calendar, AIM, todo, address book, and even telnet/SSH [$10 extra one time free].. It also has a 640x480 camera on it.. I believe there is also a program you can buy [for a few bucks], that'll sync up to Outlook.. but it also syncs realtime to the T-Mobile website, even all your pictures.
I love this thing, Ive had 4 different palm pilots in the past and ended up stop using them after a few months.. but this thing is totally different.. easy to use, not *huge* as a phone, and cheap monthly.