Mashup of Google Street View + Zillow or Cyberhomes (or all 3)
I would LOVE to see a real estate mashup that combines Google Maps Street View with Zillow or Cyberhomes home prices. That way, if I see a house I like (even if it's not for sale), I don't have to guesstimate the address and go into Zillow or Cyberhomes.
With Google Maps or Street View, I could "cruise" down X Street in Y Town. If I see a house Z, the Zillow or Cyberhomes mashup would also be at the same place (in a separate window) showing the estimated house price.
In other words, there would be a smaller Google Map and a smaller Zillow or Cyberhomes map, which operate together.
I think www.cyberhomes.com works better than Zillow, but maybe there could be 3 separate windows so if one doesn't have it, the other does.
This would be a GREAT boon to house hunters and to real estate agents trying to price an area. I think it would be fairly easy to do, although I have no experience in creating mashups myself.