Yes it can be done. You need a bluetooth dongle for your pc and some software.
This is from nokia software homepage:
Mobile BT Webcam
This application transforms your mobile phone into a Bluetooth webcam device.
You have to turn the Bluetooth ON on the phone and give the application access rights to multimedia (set to ask only for the first time) and run Mobile BT Webcam.
To give application access rights simply follow the next steps:
* 1. Open phone MENU and select APPLICATIONS
* 2. Move selection bar to MOBILE BT WEBCAM
* 3. Press OPTIONS
* 4. Go to APP.ACCESS and press SELECT
* 5. Then SELECT DATA ACCESS
* 6. Then SELECT MULTIMEDIA REC
* 7. SELECT "ASK FIRST TIME ONLY"
The webcam device that it emulates is compatible with Yahoo Messenger, MSN Messenger, ICQ, Skype etc.
For portability reasons, this application uses the back camera device in case your phone has 2 cameras.
You can also try to find some free progams via google, but 10$ is not that much.