Originally Posted by NickW
Yeah, but I foolishly assumed

that you were trying to advise the OP in the first place, rather than just state an opinion
Well, I know that the T6xx series phones and the S55/S56 sync with iSync as I've owned both of them. I haven't owned a 6620, but one of the main reasons for that is all of the reports I read from the net indicating it didn't work with iSync - do you have some different information? It's not listed as a supported device on Apple's page, and Googling turns up lots of complaints about the phone not being supported.
The 6620 is just an EDGE enabled 6600, and the 6600 is right on the isync page (
http://www.apple.com/isync/). All Series60 phones are supported in isync at the moment, even the new Sendo and the Siemens SX1 and other series 60 devices like the NGage.