Handy Techniques for Cutting Out Hair in Photoshop (via www.blog.spoongraphics.co.uk)

"When trimming out images in Photoshop, human hair or animal fur always proves troublesome and can be tricky to achieve a realistic look. Here are two techniques I use on images with both plain backgrounds, and those with a varied background tones, each achieving pretty decent end results."

Full tutorial: http://www.blog.spoongraphics.co.uk/tutorials/handy-techniques-for-cutting-out-hair-in-photoshop