Let's face it, most Americans aren't chopping wood or picking peas for hours on end these days. If you're one of the many fighting to stay fit on 15-45 minute workouts after spending 8 hours or more in a sitting position almost every weekday, this particular stretch is for you.
Holding the position for a few minutes at a time isn't remotely comfortable, but it's worth it. Your hips will feel like they were let out of a vise, at least mine did. Check out the video in the above link.
This was part of a post on a really informative blog called Mobility WOD (Workout Of the Day) by Kelly Starrett, DPT. Check out some of the other uniquely limbering stretches and exercises on his site- he's got something new almost every day, and he's just plain fun to listen to.