I was trying to use the MyMaps function to help organize the places to visit for my vacation.
Mymaps works on google earth app on iphone. However, it doesn't work on google map.
Google earth is not very useful for your travel needs.
Here is a wonderful workaround i found from this site:
http://www.skiptotheend.com/blog/2008/08/29/planning-holidays-with-google-mymaps-an-idiots-guide/
It has to do with building the my map, using the kml of the my map to send to a script at:
http://maps.taurich.org/cgi-bin/print-kml.cgi
which formats the map to a useful format and you can then print a pdf of it to view in the iphone.
This is much more functional for viewing the map itself.
However, if you want all the details of the places that you added (their address, etc.) the above instruction wont work. You have to print the map into a pdf and email it to yourself and view it in the iphone. So i ended up using the pdf+email workaround.
Google maps user interface around the map is rough around the edges and leaves much to be desired.
You could book mark the locations in Yelp and Yelp works very well by integrating the Location awareness of iphone. But all these apps are walled gardens. Once you put information in there you need to stay within the features of the app. They do not allow to export out the data to another app for exploiting the strengths of another app.