As GoogleMaps now offers geocoding services (which works really fine for European streets !), you can use it in any web application to get coordinates from a given address. The services use REST to send queries, and you can get results in XML or JSON.
I've just discovered - via dowhatimean.net - that Google Maps now displays European street names!
If you plan to use FOAFMap, you certainly would like to add your coordinates to your FOAF file.
Richard Cyganiak created a nice script that gives you the code to add on your profile with a single-click on a Google Map. Well done !