I just got a 4gb iPod nano, and would like to upgrade the headphones. I have a $50 dollar gift card @ amazon.com, and I really don't want to spend more than 20-25 out of pocket. Ipod gets used at work, and occasional business tips, so I'm thinking IEM over cans, but I will consider anything...

You guys appear to know more than I'll ever know about headphones, so I hope someone can offer me some advice. I would like to buy a pair of headphones for my computer since I share the office with my fiance, and well she can only take so much gunfire before the objects start flying. I will...