If all you need is contacts, messages (SMS) and calendar sync, then have a look at mIQ. It's a push sync service (two-way sync), which consists of two components: the BlackBerry client and the Web cloud. Media sync is also possible (photos/video), which is great as is the possibility to sync over WiFi in case you want to control your data usage while still being able to sync your data.
As the service is push, all changes to either end (on your BlackBerry or the Web cloud) will be instantly pushed to the other end. All this for free. Free. Nothing to pay for!
It's awesome, the client runs nicely in the background and since it's all push technology, will impact battery life very little.