This page has an mjpeg embedded in it:
Click here to view the image by itself.
Update: This page was created to demo a bug in Chrome 20/21 where an mpjeg stream viewed directly did not animate (chrome bug 135337). The issue has been fixed in versions >= 22. I'll leave this page up for anyone else trying to test mjpeg functionality.
Souce code for this mjpeg server can be found at https://github.com/psanford/node-mjpeg-test-server.