Simply Apps knows how to push the envelope! They just released a new application in App World called Phone Remote for the BlackBerry PlayBook. It performs a nice and simple function of remotely controlling your BlackBerry smartphone from your PlayBook over Wi-Fi. They compare it to a remote desktop app for your BlackBerry. You can then use your tablets larger screen to control your BlackBerry. The main restriction now is that it only works over Wi-Fi if both devices are connected to the same Wi-Fi network. Future upgrades will add further access.
I can’t really think of a good real world use for this if you already have BlackBerry Bridge but I guess you can run 3rd party apps that are not available on the PlayBook. For $2.99 the Phone Remote app is relatively cheap. You can pick up the main PlayBook app and the companion BlackBerry control app at the links below: