If you're a Mac user, make sure to check out Software Update. Apple has posted an update to the Bluetooth software in OS X. The update provides enhanced stability and support for the following Symbian OS based mobile phones: Nokia 3650, Nokia 7650, and Sony Ericsson P800.
Also updated was iSync. The update adds support for over 20 mobile phones from Nokia, Motorola, Sony Ericsson and Siemens. If you own a Motorola phone, iSync is able able to sync via a USB cable (you can buy said cable here). The update is free and is available from the iSync product page.