How do I Geocode 20 addresses without receiving an OVER_QUERY_LIMIT response?

Using the Google Geocoder v3, if I try to geocode 20 addresses, I get an OVER_QUERY_LIMIT unless I time them to be ~1 second apart, but then it takes 20 seconds before my markers are all placed.

Is there any other way to do it, other than storing the coordinates in advance?

No, there is not really any other way. If you have many locations and want to display them on a map, the best solution is to:

• fetch the latitude+longitude, using the geocoder, when a location is created
• store those in your database, alongside the address
• and use those stored latitude+longitude when you want to display the map.

This is, of course, considering that you have a lot less creation/modification of locations than you have consultations of locations.

Yes, it means you'll have to do a bit more work when saving the locations, but it also means:

• You'll be able to search by geographical coordinates
  • i.e. "I want a list of points that are near where I'm now"
• Displaying the map will be a lot faster
  • Even with more than 20 locations on it
• You will be less likely to hit the limit of X geocoder calls in N seconds.
• You will be less likely to hit the limit of Y geocoder calls per day.