Usability 
Crowdsourced location sharing service that uses Foursquare as a POI database. Locates you using the HTML5 Geolocation API in your iOS, Opera Mobile 10.1 or Android browser and presents a list of nearby locations where Fourquare users have historically checked in. Click a location to see a menu allowing you to share your location (name of the place and a short link to a Google Map)by email, SMS or as a Facebook or Twitter status