I was looking around the web for how to do the Portuguese purl, which I'd seen mentioned a while ago on someone's blog, and I found a great knitting site. It's KnittingHelp.com and it has an incredible number of instructional knitting videos. There are well over a hundred knitting videos, ranging from casting on to short rows and turning heels. There are also free patterns for a variety of projects. The knitter who created this site, Amy Finlay, also has a DVD that has all the site videos on it.
I found the Portuguese purl stitch on YouTube and it's not something I intend to switch to. I'm perfectly happy being a right-handed yarn thrower, so the Portuguese purl doesn't offer me any advantage.