I'm so please to see that this feature has finally launched. For quite a while now, I've wanted to be able to just say, "here's home", "here's work", "here's where we do the grocery shopping", etc, on Google Maps, so I could show mainly the family back home where everything was relative to everywhere else.
I'd started looking into the Google Map API, but lost interest because it wasn't easy to do quickly. Too much lat/long stuff for my liking.
So the "My Maps" thing is great, just what I've always wanted.