I tell my Blackberry-using friends to just get a Treo 650 and then get ChatterEmail (http://www.ChatterEmail.com/). ChatterEmail is an amazing IMAP email client with Blackberry-like push support with NO special server or desktop redirector software needed; it notifies me instantly (when I want that) whenever I receive new email. ChatterEmail also has full IMAP (including folder) support. ChatterEmail makes it really easy to quickly read messages and file them, and with IMAP support you never have to read or delete (or see as "new") a message that you've already read before. ChatterEmail plays well with Outlook/Exchange, OWA, Apple Mail, Communigate, FastMail, Everyone.net, etc. It is easily one of the most important applications I use on a daily basis.

Of course, the Treo is also a phone, and runs thousands of Palm OS applications including many that are specifically designed to help keep you organized. I'm looking forward to getting myself even more organized now that a friend pointed me to this site and the GTD book (which I bought last night).

--Steve

Full disclosure: I work for PalmSource (makers of Palm OS, but separate from Palm who makes the Treo) and (since becoming a ChatterEmail user) have met the author of ChatterEmail.