Update: Ken sez,
I was able to make a Firefox 1.5.0.x search plugin that uses the site in that Greasemonkey script. You just put the files from the zip into a folder named "searchplugins" in your Firefox profile folder. For help with locating your Firefox Profile folder go here.(Thanks, Nemanja!)
I also created a Firefox 2.0 and IE7 Google Anon OpenSearch plugin. Here's a link to the SearchPlugins.net search that shows "Google Anon Search" that I made.
You click on the "I" to install it. Here's a link to the direct source of the search plugin if you'd rather have that.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.