Display up to two Windows DirectShow cameras simultaneously
This program can display up to two Windows DirectShow cameras. It is pretty lightweight because it uses direct access to DirectShow Windows API.
Recomended "ball" test camera: https://sourceforge.net/projects/direct-show-demo-filters/
Alternative location (Penguin seems to crash): http://78.108.103.11/~fojtik/CamView/
Allows screen sharing over email, or through 'conversations' with contacts, so that when a contact receives a screenshot it's automatically displayed with its default image viewer.