To use My Location for Google Maps, just look for and click on the small blue circle in the upper lefthand corner of maps (above the street view man icon and below the compass). Google Maps should then find and place your approximate location using the W3C Geolocation API.

When  you activate My Location for the first time, your browser will display a security message, which will ask you whether to share your location with Google Maps. If you deny, your location isn’t shared with Google Maps Apps what means that My Location feature won’t be activated for you. Otherwise your browser will always determine yourposition.

It’s difficult to say how accurate the service will pinpoint your location,  so please share with us how it work for you in the comments.