Google have added a great new tool that lets you build customized search filters that run off the google engine. I made one at my site (find it here).
When you create the search tool you get to give certain web sites extra weight, or just limit to a choice list of sites. You also give certain key words some more weight and offer a choice of search refinements.
Pretty cool really. I only spent a short time with it and already it provides much closer results.
We should probably pull together one of these for the front page of PotN!