I also recommend the 6682. The Symbian OS means there are thousands of apps, both free and for purchase. I've had mine since December '05 and I've grown to love it.

I've only had a 770 for a month now, but it's worked seamlessly with the 6682. Psion is right, you can read the rs-mmc card in your phone directly from the 770's file manager--I'm always transferring images, movie clips, documents, and audio files back and forth between the devices (since I don't always have both with me).

I'm using the 2006 OS beta on my 770 and have successfully paired it and connected to the web via bluetooth. I've had only mixed results with using it to take the 770 online--it always connects, but often doesn't actually transmit any data in either direction. However, I blame Cingular's crappy MediaNET package ($20 a month unlimited access, but--in their defense--not meant to provide online access for other devices).

On my 6682, the camera works well but for one problem: in low-light indoor situations, it auto-corrects to a deep yellow color, making the photos turn out horrible. I've tried all adjustments and nothing helps. (In fact, if I turn off auto white balance and switch to the "incandescent" setting, the colors actually shift to MAGENTA, go figure.) Not sure if this is a problem with all the phones or just mine, but I'm too afraid of untrained Cingular employees to take it in anywhere, and I don't want to mail it off and risk being without my phone for 6 weeks, so I'm living with it. I use my 6682 a lot to take outdoor photos when I'm out during the day, then I auto-upload them to my Flickr account using Shozu, and it works pretty much seamlessly. Outdoor or bright-light photos look great (for a 1.3 mp camera, of course).

Lastly: it crashes. A LOT. I'm rebooting my phone about once per day. But then again, I am constantly opening/closing/re-opening/switching between applications all the time. I've learned to live with it.