I just got a Sony Ericsson T630 and wanted to synchronize my Outlook Contacts via Bluetooth with my IBM Thinkpad X40 (built-in Bluetooth). To my surprise the bundled Sony Ericsson Software does not support connecting to the phone via Bluetooth (not even irDA, only serial cable).

A quick google search pointed me to the unofficial Sony Ericsson Club's download page. There I found the Float Mobile Agent Software (FMA). And I was saved. This piece of Open Source!! Software is just plain amazing.

Simple to install, only one single exe file, the explorer style UI presents shows all content stored on my T630. I could easily configure FMA to use Bluetooth, it also offers irDA and Serial Cable connection options.

Besides syncing contacts with Outlook, which was my main objective, it syncs also images, ring-tones and so on.
Another very geeky feature of FMA is showing the phones temperature. FMA also lets users create SMS messages on the PC and send it out via the Phone.

I was so pleased with FMA, I immediatly donated to the project.