I've been using SimpleGeo for doing some of my place data queries for a location-based app I'm building. They currently use Factual's data set. From what I can tell, there is no way to do partial text queries on place data, probably because of limitations on Factual's end.
The kind of query I mean is that "Starb"
would return results for Starbucks in an auto-complete.
Testing out Google Places API yields the same results. Querying "Bullf"
for Bullfrog Brewery near Williamsport, PA turns up nothing. Querying "Bullfrog"
yields the correct result.
Do any geolocation/place APIs support this kind of partial keyword query?
Google Places does have an Autocomplete API that will return results based on partial keyword queries.
You can view the documentation here:
http://code.google.com/apis/maps/documentation/places/autocomplete.html
Also there's a demo and a blog post about the Places API with Autocomplete here:
http://googlegeodevelopers.blogspot.com/2011/05/places-everybody-show-is-about-to-begin.html