With the wide acceptance of Wi-Fi, webcams have gained a whole new dimension. With the proper configuration of a laptop, a website can be configured to provide access to a camera only when it is transmitting. A webmonkey can tote a camera around with him and transmit images anywhere he can find an open access point.
I personally recommend a velcro laptop configuration, which allows you to mount the webcam easily, and take it on the road. I use booruWebCam (http://www.booru.net/) because it is small, simplistic and unobtrusive.