A simple method we often use when developing changes to web applications for which we don't have control over the DNS is to let the testers add a line in the Windows hosts-file that points to the public IP address of the test environment (for one, McAfee uses this method for their staging environment).
I was wondering whether a similar method is possible on the Android and IPhone, i.e. to add a host lookup entry for a hostname. This would make testing certain webapps quite a bit easier for us.