Tuneband for iPod nano 4th Generation, Armband Compatible with Nike+iPod System
I bought this arm band for my girlfriend for Christmas.  She likes that it is pink.  She also told me that it is very handy.  The only issue is what to do with the extra cord from her headphones.  What she does is wrap the cord around the arm band a couple of times and the reduces the slack and then it is not in her way while working out.