This is an interesting event in upstate new york - it's FREE to educators, though travel may be an issue. They had a pretty good set of speakers the year I was there (even though I was among the speakers ;-) and it's very focussed on providing things that can be taken away and used in classrooms. I'd recommend GLS a bit more, but this one is a pretty close second.
Josh Sheldon MIT Scheller Teacher Ed. Program/Education Arcade MIT Center for Mobile Learning