The 5th Mars Society was back in Boulder, Colorado in '02. The first two were in Boulder, then Toronto, then Stanford. I have attended all the ones in Boulder (about an hour from where I live).

The Mars Society has matured in 5 years. The first big A-Ha was when Zubrin published his '96 book The Case For Mars (which I highly recommend). This book showed definitively that a Mars mission could be done safely, cheaply (tens of billions of dollars, rather than 450 billion, the first NASA estimate that then-President G. Bush, Sr. received, which understandably killed interest in a manned Mars mission.), and using available technology.

For space-philes, this was enough. If there were no technical barriers, and no monetary barriers - why wouldn't we go? But as Zubrin realized then, and more strongly now, getting the public and political support are the biggest hurdles to actually doing it via NASA. Specifically, he two biggest obstacles are:

1) We're swimming upstream. In the early 90s, everyone in Washington "knew" that a Mars mission was financially impossible. We now have to reverse this opinion - it would have been much easier without the original silly $450 Billion dollar price tag from NASA.

2) Rather than going to Mars, NASA decided to spend a lot more, and accomplish a lot less, and put the ISS in orbit.

	Dr. Zubrin addresses the convention on Opening Day. Even though Mars Society membership has increased to about 5000, the conference attendence has dropped since the first couple of conventions.
There were a few vendors at the conference, selling space art, books, T-shirts, etc.
	Someone (I don't have the name, sorry) giving an update on her 2-week stay in a M.A.R.S. hab.  The biggest accomplishment of the Mars Society to date has been the building of M.A.R.S - the Mars Analog Research Stations. M.A.R.S is a model of the proposed Mars mission lander, from which Mars Society members conduct mock missions on the Martian surface. There's one of these on Devon Island in the Canadian Arctic, another is being built in Utah, and at least two more are planned around the world (Europe and Australia, maybe?). Through these experiments, the Mars Society has obtained considerable knowledge about the nuts-and-bolts of efficiently planning and conducting a real mission.
Dr. Chris McKay is perhaps the best-known of the NASA attendees. Here, he is giving a talk on a proposed '07 mission to the North Pole of Mars. This conference is well-attended by NASA folks, and yet, NASA receives a fair amount of criticism. There shouldn't even be a Mars Society, we should have already gone there - I always wonder how the NASA representatives feel about their agency drawing so much friendly fire.
	A mock-up of a Mars spacesuit
The Saturday night banquet was entertained by the Extremeophiles, an ad-hoc band formed during a M.A.R.S. mission. They were surprisingly good!