Geo-location check-in service SCVNGR struggles to compete against Foursquare and Gowalla, but they have stepped up their location database with Google Places API integration. Google Ventures is an investor in SCVNGR.
SCVNGR is a mobile application that works on the iPhone and Android. SCVNGR is also expanding to 80 countries. SCVNGR plans to add a game layer on top of the geo-location data. SCVNGR launched about 20 weeks ago and they have about 500,000 users.