Keep in mind that I've never owned a Treo or web-enabled cellphone before...

One of the quirks I found when I got my 600 was that the SMS feature didn't work. After composing a msg and hitting SEND, it pops up an error saying that "This service is not yet available, but will be shortly", and to try using ShortMail instead. But I don't have a clue what that is or how to access it. I find no mention of it in the manual, nor can I find any other reference to it on the device itself.