Dimdim 4.5 is now out. Dimdim is a web meeting host and is absolutely free for up to 20 participants. The Pro version scales from $99 per year for up to 20 and $495 per year for up to 100 participants.
It is much improved from the beta that I used at the beginning of the year. And one smart and useful new feature is the ability to open web pages and scroll them in the shared space, and everyone can see the page. Or you can open a YouTube video in the space and every participant can see and hear it.
You can record, incorporate PowerPoint presentations, use video and audio, laser point and annnotate. It looks great and well worth having a play with. It looks to me like it will give Elluminate or WebEx a run for their money and has the benefit of no software to down load or configuration to worry about. It just runs straight out of the browser.