The Radiant google_maps extension is now good to go. The the basics have
been finished. You can create a Google Map. Add Markers and add content
to a single info window using your favourite filter and Radius tags.
An extension that allows you to create, modify and embed google maps
into your Radiant site.
It has been added to the extension registry here:
Sean Cribbs for putting up with incessant questions on IRC.
If you have any questions / problems / issues then fire away, it has
been pretty well tested so there shouldn't be anything major.
Radiant mailing list