The estate agent, KFH, has launched a boundary based search. You can draw a boundary on the map and then receive property alerts based on that boundary. I haven’t seen anything like this in the mainstream (but perhaps I’ve not been looking too hard). It will be interesting to see if other estate agents follow suit with the same idea. These kind of spatial queries have been around for decades in GIS – has its time come for the mainstream? Will people be interested? Will it be a successfuly way to find a house? What if a house lies just outside the boundary (say a metre)? – possibly you’ll miss it.