It looks like adding "&gl=" to the request disables this feature.
Judging by my quick experiments (see below) it's using gl=au by default.
http://www.google.com.au/search?q=university | australian results |
http://www.google.com.au/search?q=university&gl= | world results |
http://www.google.com.au/search?q=university&gl=au | australian results (same as australian results above) |
http://www.google.com.au/search?q=university&gl=uk | uk results |
The following searches, however, seemed to have only minor variations, with no obvious country biases:
http://www.google.com.au/search?q=smtp+server+component
http://www.google.com.au/search?q=smtp+server+component&gl=
http://www.google.com.au/search?q=smtp+server+component&gl=au
http://www.google.com.au/search?q=smtp+server+component&gl=uk
The effects of the GL parameter seem to be different from using the
* The web
* Pages from Australia
options sometimes available on the left of a google search.
Also note, something I've done (I suspect clicking on the "The web" link) has changed the results I'm now getting for the GL-less seaches.
Oh, I found out about the parameter from http://www.searchmasters.co.nz/articles/204/country-bias-in-google-search-results/