*d Last time I looked I couldn't find my car (3 months ago), now I look and it's in my driveway (of the home I bought in April, 2010 ... which was 20 months ago). So how often does their satellite update to the web?
They get the images from multiple sources, so there really isn't a regular update frequency. More populated areas will get updated more frequently, too. If you use Google Earth, you can scroll back through older satellite images.
If I go to google maps and look up my parents address, then go to street view, I can see my dad's old pickup, which is now my old pickup for about 3 years now, in their garage.
My dad and his girlfriend are currently on google maps online waving at the truck in about 3 pictures. They were taken somewhere near orlando at her foster mothers house. Pretty cool.
My parents house (they lived there for almost 6 years now) accoring to google maps is still being built.
My house is still a dirt field and so are a bunch of others that have been built for a few years now already.