From your Favorites view, drag down on the screen to reveal two additional choices—“Add to Favorites” and “Request Desktop Site.”
Choose the latter option, and voilà! Safari will ask whatever page you’re on to serve you piping-hot, full-featured website goodness.
This hasn’t worked on every single webpage I’ve tried, but it’s been successful often enough that I’ve found it very useful, especially when I start getting frustrated with the limitations of certain mobile sites. If the iOS version of your site makes me tap on an image to open it before I can zoom in closer, I’m looking at you. Or maybe “glaring at you” is a better way to put it.