php - Converting coordinates into map addresses -

i developing gps server , tracking system:

1. how can convert latitudes , longitudes data got gps tracking device address data client application report displaying road names instead of coordinates?
2. how can map coordinate data tracker position displayed on map i.e. google maps or vector maps?

i'll highly appreciate answers or suggestions

1. use reverse geocoder. http://code.google.com/apis/maps/documentation/geocoding/#reversegeocoding

2. use mapping api google maps. http://code.google.com/apis/maps/documentation/javascript/