Auto fill out form via URL & POST

I've been searching my heart out trying to find a website I frequently used years ago.

The site would let me give it a URL and then it would rewrite the target page for display on its server, let me fill out the page, and then kick out a URL with all the POST parameters when I subm开发者_如何学编程itted the page.

For example, let's say I told it to go to Google.com and searched for "blah" - it might kick out a URL like:

http://www.google.com/#q=blah

Does anyone remember what this site is?

The Tamper Data extension for Firefox will let you modify POST parameters before sending forms away - it's certainly easier than going to a different page!