Google and some other sites allow the syntax

site:amazon.com

as part of your query. For multiple sites, you need to separate them with OR (in capital letters) and probably use parentheses:

(site:amazon.com OR site:newegg.com)

Adding 98 more may run up against a restriction at some point. Have you tested manually?

Once you have your list in this format, you could create a new search engine plugin by copying the existing one, modifying the query, and saving it as a new one. At least in theory.

Thanks for the reply. The web interfaces don't support 100+ SITE: entries. So that won't work.

I have never tried to do a search engine plug-in, but will look into that.

I'm surprised that someone hasn't found a solution other than the Google Custom search to restrict their teenagers (or husbands) to known-acceptable sites.

In this case, I'm interested in only searching known vendor sites for their electronic parts. I want to avoid all non-vendor sites and ads.

Hi mistevens, a search plugin simply automates the process of adding parameters to your query, and unfortunately cannot bypass the limitations imposed on particular Google services.

It does sound as though Custom Search is the best approach, and then you can create a search plugin to default your searches to run with that particular set of parameters.

If Custom Search ultimate is unsatisfying, you could try modifying my Greasemonkey user script, "Google Hit Hider by Domain". Currently, it works by hiding domains you want to exclude, but it could be rewritten to only show domains you want to include. This would require some knowledge of JavaScript to accomplish.

My script doesn't block ads (and I've discovered that the ad URLs are more complex), but I'm sure you could find plenty of add-ons to take care of those.

Script information: http://userscripts.org/scripts/show/95205

Of course, there are plenty of filters that kick in once you click a result and try to navigate to the site. A popular one is BlueCoat's K9: http://www1.k9webprotection.com/.