SauceLabs allow the running of a Selenium tests in the Cloud. It requires the use to sign up and get the Sauce credentials, username and access key. The service is free for limited use, and scales up to offer various paid packages, depending on the monthly minutes used. Sauce access is provided via a bespoke SauceWebDriverProvider which allow the Sauce credentials to be provided via system properties, SAUCE_USERNAME and SAUCE_ACCESS_KEY.
A fully functional example webapp using Sauce is provided in JBehave Tutorial.