With the Google Maps API, you can plot custom overlaid icons and the API gives you control over shadows and the orientation of the icon (the speech bubble's orientation and characteristics).
Some important observations on first glance:
- There is no routing API. It's just mapping.
- There is no geocoding.
- There is no local search.
Google has offered this legitimate API as part of a web service but the back end data steers clear of geodetic information paid for by Irish citizens. Wouldn't it be wonderful if all Irish Ordnance Survey maps were released into the open domain for remapping with applications like the Google API? Doing that would boost tourism right away. It's a shame that Irish politicians don't get this fact. I wonder if any TD has actually used a Google map for planning a holiday or a business trip.
Google Groups -- "Google Map API discussion group"
Bonus Link: Yahoo! Maps Web Services