Get the 7650 (or a P800.. though I've never tried one).
See
www.my-symbian.com for a list of 7650 goodies you can get... I've got a fairly decent web-browser with https support ("Doris"?!), a multi-protocol messenger client (tipic ME) and some games. Plenty of toys
Of course, the P800 is triband and also has Putty (ssh) ported to it...
The 7650 works pretty well as a phone IMO. I don't have a lot of time for things which don't do the basic job well - like the O2 xda, for example. The thing frightening me about the P800 is whether the keypad-over-the-touchscreen flip bit actually allows me to text as fast as I can with real keyswitches.
The T68 is bloody awful - well, mine was, and I know plenty of other people who regret getting one. Triband, yes, colour, yes (well, a bit washed out) - but forget signal, actually making calls without reboots and texting so slow that I could end up two lines ahead of the screen and have to wait for *10 seconds* for the phone to catch up. And yes, I did get the software upgraded on it to see if it helped.
Hugo