anyone know of a script that will let me specify which sites I want in my own search engine? I want to build a search engine with specific sites and have my own index of those sites so anyone can search just those sites. something very customizable...
Orca Search by Brian Huisman. That's what I use. Direct Download: http://www.greywyvern.com/code/php/orcasearch_2.2a.zip
http://www.greywyvern.com/search?q=something It's all CSS so you can style it how you want - I don't think he has done a great job at that on his own site but don't let that put you off. It comes with its own spider and you can set the algo parameters yourself.
Depending on how advanced you need it, I would either go with the new Google Coop project (let's you create your own custom search engine), or if I wanted something more advanced I'd use a solution based on Nutch. (I can't link to stuff yet, so just google for them)