When working on projects that use maps (like integration with Google Maps),it is very convenient to use specially designed icons. Maki is a free set of icons in the form of places of interest, which is perfect for a map-based interface to the Internet.
The set includes 73 icons that are available in 3 sizes, formats PNG+SVG. Besides the standard markers, here are airports, bus stations, police stations, restaurants, grocery stores some other icons.
Web site: http://mapbox.com/maki/