Try
Livecast. I used to use it next to a laptop that had no webcam, worked well. The bandwidth is configurable so you can adjust it if your signal strength is low. You can also save and share webcasts from the website.
After you set up an account (free), you can set public/private options. Send a url to friends to watch your live broadcast. Cab installer (I think) to PPC, browser links to various media players.
Hope this helps.