Originally Posted by idontknow!hehe
It depends on the webcam. Most will come with software to install that will allow you to take snapshots with it. If not, you can buy a 3rd party program to do so. Some webcams will also have a button on them to press to take a snapshot. However, you will need to have the software installed first though. Read through your webcams instruction manual for it's exact details on how to do it for that particular webcam with it's software.
Hope this helps you,