qwerty keyboard smartphone

Is a QWERTY Keyboard very vital for a smartphone??
I’m thinking of buying a smartphone that allows me to send emails, view documents etc and I’ve been eyeing the Dopod S300 which unfortunately does not have a QWERTY keyboard. So I really need advice on how necessary is a QWERTY keyboard for a smartphone or can one do without it?
I like the keyboard on my Palm Treo 650. Honestly my Palm does everything, it has a web browser, plays MP3’s, has MS Word, a camera and video recorder….lots of other stuff. My friend says he likes it better than his Blackberry. You can pick on up on Ebay for less than $250.
HTC-S621 Unlocked GSM Smartphone with QWERTY Keyword