I remember hearing about this product awhile back but I then realized we have never actually mentioned it on BerryReview. Greg & Remzi also let me know that it has been improved in recent versions to make the app more responsive. viaDock lets you control your BlackBerry from your PC whether it is a Mac or Windows machine.
The $39.99 price tag is pretty pricey but there are no real competitors other than the $99/year Bayalink Liberty since Rove Mobile stupidly took their free viewer off the market. This might be the closest you get to having BlackBerry messenger on your PC without RIM releasing a client. 
The app easily connects over Bluetooth & USB and gives you access to quite a few functions:
- Create a fully integrated environment: Use your PC and BlackBerry applications through one single system when at the office, home or anywhere you use a PC.
- Connect quickly and easily: Connect via Bluetooth or USB to your desktop or notebook PC.
- Share clipboards: Easily copy and paste text between your PC and BlackBerry applications.
- Quickly switch between BlackBerry applications: Use the application launcher or menu shortcuts to start using any application running on your BlackBerry.
- Dial and receive phone calls: Use on-screen phone controls to quickly make and answer phone calls, enable and disable hands-free talking and turn on and off mute.
- Know who is calling: Get instant notification of incoming calls while using viaDock, or through mini view when using other applications.
- Monitor your BlackBerry status: Always know your battery and radio signal strengths at a glance.
I am really digging the little dock that tells you who is calling and lets you take a call using your PC. This app is definitely not for everybody but the idea is really cool! They still have some bugs in the app like the numbers do not work right on the Storm but it is worth giving it a spin if you are interested.
Check it out on Impatica’s website at this link. They even have a version for car dash docking stations which would let you use your BlackBerry with a big touchscreen.
Impatica viaDock – Control Your BlackBerry from your PC or Mac
