Sometimes, I use web sites that have forms that are not so user-friendly. If only there was a more convenient way we could just manipulate the URL-string. A quick search yielded this Parameters Editor – an Add-on for Google Chrome. You just click on the “EDIT” button next to the URL and a form pops up with all the URL Parameters.
You can find the Add-on in the Chrome Store.
I used it for Couchsurfing.com, that lets you search online by a certain radius (up to 50km); with this tool, I can set the radius (and the lat/long coordinates for that matter) to whatever I want, yielding global results (the maximum radius appears to be 4192).