BookSync is an interesting Windows Mobile application that allows you to sync your contacts with Facebook. The application allows you to synchronise the pictures of the contacts in your WinMo device with the profile pictures of your friends on Facebook. The latest release allows you to sync birthdays and names too. 
On the first run, you need to authenticate the application with your Facebook credentials. Once you are good, you’ll be presented with two lists to match a mobile contact with the appropriate Facebook contact. The latest release also features auto-matching of the contacts. This matching is then stored for future synchronizing.
Though this is an early beta release, the core functionality works and the developer promises UI and other enhancements to the application.
BookSync requires the .NET Compact Framework 3.5 on your device. The application can be downloaded from Facebook apps directory or the homepage.
Bonus Tip:
A similar Windows application, OutSync, syncs photos of your Facebook friends with matching contacts in Microsoft Outlook. If you sync your WinMo to your PC/Exchange Server, it achieves the same purpose.
