Well, I didn't win an IPod through pop-ups, but I did get a free IPod!
When I bought my first Volkswagen Beetle, a 2000, it came with a free IPod and all the accessories. Volkswagen was running a promotion with Apple and for awhile, anyone who purchased a Beetle also got a free IPod. I eventually gave it, (the IPod, not the car!), to my oldest daughter. I never could figure out how to put songs on it.
I actually know someone who got a free Ipod from those popups. Some actually do work. But the Ipod isn't exactly "free". The pop ups ask you to take a lot of surveys and most include you purchasing something. Like you can purchase a $10 gift card to Best Buy or what have you. Also you have to enter in real information and use a real credit card. That makes me very skeptical. But I have heard of it being done.