Google have always had some form of mapping interaction overlay (google up Cognation pty ltd on google maps and you'll see what I mean).
But now they have implemented this on a whole new level. Check out google My Maps.
Basically this application allows you to share maps with your friends and family (I placed mine on my www.collins.net.pr/photo website), you're able to add routes, notes, points of interest and thumbnail photographs (supposedly...wouldn't work when I went to add a thumbnail photo but you can check out the photos I took on my online photo album-I've got a feeling it may have been because of the extended urls).
There was no indication Google were hoping to place advertising on your map...I can only assume this is coming.
Either way neat concept; Have fun checking out a walk I took on Sunday from my apartment on 72nd and York up to central park with my wife Jodie and Lou Lou our dog.
P.S. Btw by the time I finished all this would I do it again...hmmm maybe not, probably as only a few members of my family have flown over so it's a good idea to get a lay of the land however you can tell it is very early days for google My Maps as the tools are a little clunky.
P.P.S. Make sure you click on the map in satelite view as well, adds a new perspective.