How do I create a forum in a Google Sites website?

I did a comparison about 6 months ago between Yahoo groups and Google groups. I set up two identical groups and played with them for a couple of weeks before going public. I found Yahoo was superior for ease, fewer spybotting ads, more storage, and easier set up for group members. I have not looked back.

Thanks, but my google account is required under my circumstances and a Yahoo account is not neccessary. Besides, it needs to be in Google Sites, not Groups

I am not sure as I have not got to use google sites before, but do they allow you to put any java script or php code in there? If so then you maybe should look for just an open source on in there.