Selenium cannot be used to test remote sites becuase browsers have cross-site scripting protection which prevents you from modifying the content from other domains. What happens when we fool the browser into believing content comes from a given domain? An extremely simple squid configuration can do just this.

I wrote one test. This test visits technorati's homepage, searches for 'barcamp' and verifies that a text string exists on the search results.

Steps:

1. Tell Firefox to use my squid proxy as an HTTP proxy
2. Visit http://www.technorati.com/_selenium/
3. Run the tests

Simple, right?

The squid proxy intercepts any requests for '/_selenium' and redirects them internally to my selenium web server. This has been tested in IE, Firefox, and Safari with 100% success over vanilla http. HTTPS probably doesn't work for obvious "Duh, it's encrypted" reasons. Squid can fix this aswell with ssl reverse proxying.

If I run my single test, the result is something that looks like the following (Firefox and IE, respectively):