An internal external search engine

Just wondering how useful this might be?

Google has their ajax search, which is nice. But what if you have a large site that is behind protection and what if you dont want those ranking feature, but rather have users rank their findings on your site? You'd might have to settle for building your own or using the CMS's builtin. So I started building several appliations on my server to do this and wonder if it might be useful to anyone else.

This is something I've already began working on and I wonder if this is a good enough of an idea to actrually profit out of? Maybe add advance features like how often to crawl their site, search statistics, etc?