Birdie Sync

Birdie Sync is a good piece of software that synchronizes with our daily activities with the mobile phones.

They support:
Windows XP, Windows Vista 32 bits
ActiveSync 4.5, Windows Mobile Device Center 6
Thunderbird 2.0
Lightning 0.3
Sunbird 0.3

Windows Vista 64 bits is not yet supported

They also have an security policy and it says that you must have a mobile which is unlocked. This means that you should be able to install any unsigned software to your mobile.

Download the desired versions from its home page.