I recently started using http://www.browserstack.com/ http://www.browserstack.com/ , after finding out that my web app did not work properly with touch devices

I recently started using http://www.browserstack.com/ http://www.browserstack.com/ , after finding out that my web app did not work properly with touch devices (e.g. the iPad). They let you your any browser and OS you can think of (including iPad Safari), and surprisingly, the latency is actually not that bad (they're basically giving you a remote desktop by streaming video). If you want to Do It Right™, and have the time to set it up, I think the best thing to do is to set up a Selenium (http://seleniumhq.org/ http://seleniumhq.org/) grid that has either VMs are standalone machines running all the browsers that you want to support. Then you can write tests that automatically verify that important features work everywhere. This doesn't completely obviate manual QA testing, but it can help a lot.