Why an API? The dataset is pretty small. Converting it from Excel to JSON and putting it up for download as one file would be more useful for any task I can think of.
Clustering the markers will greatly improve performance: <a href="http://google-maps-utility-library-v3.googlecode.com/svn/trunk/markerclusterer/docs/examples.html" rel="nofollow">http://google-maps-utility-library-v3.googlecode.com/svn/tru...</a><p>I actually had this same idea a few months back. I'm the developer of truxmap.com, a real-time food truck map, and I wanted to export the concept to farmers markets. However, the USDA data set isn't sufficient because it doesn't include days of the week and times. Nevertheless a map i easier to read than a table.
I have an app in the iTunes Store that covers farmers markets in CA, OR, and WA. If someone wants the code as a starting point for building an iOS app on top of this API, let me know. (I have no time to update it at the moment).<p><a href="http://itunes.apple.com/us/app/farmersmarkitwestcoast/id413973626" rel="nofollow">http://itunes.apple.com/us/app/farmersmarkitwestcoast/id4139...</a><p>I can also get some promo codes if anyone wants a free copy to try first.
Great idea! Why is it great? Because it's a technical achievement that is easily understood by the normal web user. It shows how technology can be used in basic ways to make information easier to use. Well done.