Dimdim is a free and open source web conferencing solution that hopes to compete with WebEX and ASAP. Although still in alpha, this product shows a lot of promise. The software is easy to setup and manage and serves up meeting content from the system that you install it on. The conference manager application runs in a web browser (MS IE only at this time but Firefox exensions are in the works) and the conference manager can upload only PowerPoint presentation at this time. The attendee only needs to have a web browser with Flash. We tried it out in our office recently and it worked very well.