Here's a useful tool, and and example of the generous spirit of the internet! For a while I'd been looking - unsuccessfully - for a tool that would limit Google searches to the sites that a given page (e.g. a subject portal) links to. I mentioned this to Philipp Lenssen, who is the creator of findforward.com, feeeds.com and the Google Blogoscoped blog. Within 24 hours he came up with the desired tool, and it's called NeighborSearch! Many thanks,Philipp!!