This exercise is designed to work your upper back and traps. This is done with the same motion as a snatch, but not done exposively. I believe some have called it a Muscle Snatch, but that name just makes me grin too much.
To do this exercise, take a wide grip and begin by performing an upright row. Be sure your elbows are higher than the bar. Once you pull it to your chest, rotate your hands and elbwows so that the bar is moved overhead and arms are outstretched.
This is a easy movement, but not one that you can do a lot of weight with. I like doing this for higher reps (10-20) and will give you a massive trap pump.