This is what makes Google applications so powerful: their ability to get hacked…in a good way. Google Maps has been the Google h0tness for this year and is the latest application to get a major reworking from the outside world.
This site shows you how to use a couple of inputs and XML files to get Google Maps on your own webpages. Not sure how legal this is, but it sure is fun to see people figure these things out.
Even cooler is that you can display custom HTML in the info popup window. Checkout the sample map to see it in action.