In reply to PaulTclimbing:
It's easy once you have a grasp of how to do it, took me a while to find a solution. It's just an IP camera (Trendnet TV-IP310PI). You have to set up your router to port forward so that it can be seen through your firewall. Unless you have a static IP, then you also need to use something like www.noip.com to allow people to locate your camera and make the stream visible from the internet.
There are various sites that enable broadcasting to multiple users (e.g. Angelcam). I initially used the free option of ipcamlive.com when I set up the camera over 2 years ago. I now pay 15 euros/month, which gives pretty good reliability and allows the video to be relayed without slowing down your own broadband connection (only 8Mb here in Glencoe and 0.15Mb uploads). The only issue is that noip.com use a process running on your desktop to forward your current external IP address, if you shut down your PC, or that process, the camera is no longer externally visible.