If you develop Web sites or even pages, you must know about Browsershots, Cross Browser Testing, and Perfecto Mobile. Many of you already do; that's great. We all need to be familiar with them, though, take advantage of them, and be ready to pay up for their extra services when they make sense. These three sites are simply that indispensable.
Don't whine that it's a pain installing different browsers and testing your site against them all; just hand over the job to Browsershots. The same, but even more, with mobile handsets, and Perfecto Mobile--especially with handsets, which are fundamentally a consumer fashion item whose engineering is, at best, capricious. I've managed testing teams to eyeball until late hours the surprises that show up on scores of little handheld screens. I'll likely do it again ... but only as a last resort, after we've already wrung out as many problems as possible by leveraging Perfecto Mobile.
There's plenty that these sites can't do, there are reasons I don't use them on several of our projects, and I'm sympathetic to the argument that most programmers are poorly equipped to judge user interface matters, let alone navigate the shoals of device incompatibility. If you're not familiar with them already, though, invest a few minutes to learn how these sites can automate for you capture of the screen displays of live sites. Do you want your first view of your site in a particular browser to be after a customer asks you why it looks the way it does?