Been poking the W810i this evening, trying to get it to synchronise with my PC for things like calendar and contacts. Gave up on the official software quite quickly, as it seems to be utter pants, only supporting Outlook Express / Windows Address Book. Found a link to some software called MyPhoneExplorer, and it seems to do everything that the virtual tin says it does, complete with calendar and contact sync (and I now get why Dave loves this feature of his Treo), send SMS from the computer, full contact editing and more. It only works with the Sony Ericsson phones, but it’s a very nice little tool. The really nifty part about the calendar sync is it talks to Thunderbird, Google (which I don’t use), an iCal file or the application itself. Since I use Thunderbird on the Windows box, that works quite nicely for me.
Pity the transfer over the USB cable is so slow, even on a USB 2.0 host controller, but I think that’s the phone itself.