There is a really handy extension for chrome called Redirector which allows you to specify regular expressions which match against URLs seen by the browser and automatically hijack/redirect your browser to a different URL. It's useful in situations such as developing code against a payment processor which only allows you to specify one redirect URL (typically set to a server). With "redirector" you can send the redirection wherever you want.
I'm working on writing Selenium tests against a checkout process and, with Selenium WebDriver, a new instance/profile of my browser is launched with each test suite (without extensions/plugins/etc.). I use Redirector in development, but this isn't an option in test. I am wondering if there is some kind of OS-level version of Redirector I could use.