Google Maps with My Location (beta)

Their website says See your location on the map, with or without GPS. Save time and tedious keystrokes finding where you are, what's around you, and how to get there. Why the uncertainty? The My Location feature takes information broadcast from mobile towers near you to approximate your current location on the map - it's not GPS, but it comes pretty close (approximately 1000m close, on average). We're still in beta, but we're excited to launch this feature and are constantly working to improve our coverage and accuracy."

So as you can see from the picture the dot is not showing me where I am, (the dot is around St James somewhere when I'm currently located in Soho, London and the accuracy of the location data can be up to 5km off. So rather than telling me i'm in Soho it could be telling me I'm in Islington lets hope they improve the accuracy soon.