I have used
Yawcam with some success - it is free and fairly straightforward to setup.
It is easier to set up if you have a direct internet connection, rather than through a router, and streams direct from your PC which acts as a webserver, so you don't need your ISP webspace, although you would be able to link to it from your site.
Streaming will require a reasonably fast (broadband) uplink, but as you have been using Messenger I assume that you have sufficient bandwidth.
Another one I have used in the past is
VisionGS which does stream via an applet on your ISP website, but I think that you now have to pay for the streaming version.