It's nice when something you worked on becomes practically useful :)
My partner works in a cellphone store, so he gets lots of shiny new demo hardware. Right now he just got an HTC Touch Diamond (pretty nice phone actually) for two months. The phone he uses regularly is a Blackberry Curve. So he needed to synchronize all his contacts from the Blackberry to the Touch.
Try doing that in Windows! You'd probably have to set up the Blackberry software to sync from the Blackberry to Outlook, then use ActiveSync to sync from Outlook to the Touch. Bleh. Pain.
I just grinned, grab them both, plugged them into my PC, set up a partnership with the Touch with synce-trayicon, ran Kitchensync, set up a sync group, added the Blackberry and Windows Mobile device plugins to it, and hit synchronize. Bing, done. Took about thirty seconds. No intermediaries, it just syncs direct from the Blackberry to the Touch.
EDIT: Ok, so I spoke too soon. It turns out the contacts all show up on the WM device...sans phone numbers. :) But I have figured out why that is, hacked up a quick fix, and reported the bug to synce and barry, so it should get fixed soon.