The Google Geo Developers Blog has just published links to a number of articles on developing with Google Maps:
- Fun with MVC Objects
- Geocoding Strategies
- Using Google Sites to Host Your KML
- Developing for Mobile Devices
So far I have only managed to browse through the Fun with MVC Objects article. The article is a step by step guide to creating an adjustable radius tool. You can see the tool in use on this great Twitter Map.
Basically the Twitter Map uses the radius tool to let the user define the region within which they wish to search. The article has other suggestions about how you might use the tool.
I'm sure the other articles are just as good and just as useful.