Zonums Software has just released several Google Maps mapplets; click on a link to add it to your Google Maps MyMaps applets list:
Pointer: Click on a Google Maps point, and get the coordinates in latitude/longitude or UTM.
Digitizer: Click on points in the map window, and create a list of their coordinates (UTM or lat/long) for export to another application.
The last two functions are also available at Zonums in the stand-alone Google Maps app Digipoint 2, which offers additional features like data export in multiple formats (KML, GPX, shapefile, etc.).