I've open-sourced my little Google Maps email signup gizmo that I use on my live page and when visitors sign up for things (blogged about it here and here.) You can grab the script here:
Brad's Mappy Email Signup (google code project)
It's another quick and dirty project from Brad Labs, cleaned up a bit from my implementation of it. But it's been working very nicely and I'm super happy to have the data for live show planning purposes instead of relying on Eventful as a middle-man.