If I’ve learned one thing about conferences over the past few years, it’s that the Skepticon model works. It’s a hell of a lot of work for the student groups (!!!) to organize, but if they can make it free and open it up to the general public, people will come in droves.
This is all dependent on people donating money for the cause — to cover things like the travel/lodging costs for speakers (who tend to come for free) and the space (unless the university provides it at no cost to the student group).
We’ve seen this work for Reasonfest in Kansas, too.
Now, Freethought Festival 2012 is coming to Madison, Wisconsin April 27th-29th:

They have an awesome array of speakers. I’m excited to be one of them and I’ll be presenting a new talk on How We Can Help Young Atheists.
Like I said, it’s a free conference — but you do have to register.
Please consider chipping in a few bucks using the PayPal icon on the left side of this page. Those contributions are what allow these free conferences to continue.
(via AHA at UW-Madison)