Whether you're still looking to be convinced, or you're just curious, this article (by Richard Bloor) on the Wireless Development Network will prove interesting as it takes a little closer look at the UI behind the 7650, the 3650 and possibly others also...

Is it easy to use?
"One interesting experience of the Nokia 7650 regards a person who has always had access to email and a digital camera, but has been an infrequent emailer. The process of turning on the PC, downloading the pictures and writing an email has always seemed more effort than getting a set of photos developed, scribbing a short note and posting them, because these services have always been accessible as part of the daily routine. Since she has had the opportunity to use the Nokia 7650 she has probably sent more emails in a couple of weeks than she would have done over the previous year. The immediacy is probably the key factor, see it, snap it, write it, post it all in a matter of minutes".