Stumbled across this Firefox plugin the other day and have found it quite useful. Lets you see what the Google search results you are viewing look like from different geographical locations.
https://addons.mozilla.org/en-US/firefox/addon/google-global/
Ed
this is the first plugin i install when I get a new browser
That looks handy, but it's not compatible with FF5 and unfortunately hasn't been updated since April. I hope they update it soon.
But you can still get it to work in FF5 by fiddling around with the settings.
http://www.reecreate.com/blog/2011/06/22/howto-enable-incompatible-add-ons-in-firefox-5/