If you like to rely on Bluetooth for syncing your devices with your Mac and don't want to use several different applications to do it, then iSyncIt is convenient all-in-one solution.
iSync is a small menu bar application that allows you to sync your devices more easily and even activates your Bluetooth on and off automatically which saves valuable battery power if you're working on a Macbook. You can either elect to synchronize at any given moment or schedule syncing to a time of your choosing. However, the developers note that it only works with Apple's internal Bluetooth devices and not external ones.
iSync supports Growl alerts so you'll instantly know when syncing has been achieved or is complete. However, there's very little support for specific applications. iSync is ideal for things like iCal and Address Book contacts but not much more. Some users have also reported that it doesn't support certain mobile devices, particularly Sony Ericssons.
iSync is ideal for those that only need to sync iCal and Address Book contacts with their mobile device although those seeking more should look elsewhere.