There are callus removing medications that pretty much dissolve the skin, but I don't recommend using them on your hands because they can sometimes leave painful cracks in the healthy surrounding skin.
For you, I would move the iPod to a different spot and apply deep moisturizing hand cream twice a day. Eventually, the callus will fall off in probably about 6 weeks. Don't pick at it, don't peel it off. Just moisturize it, remove the cause of the callus, and let the regrowth cycle of your skin take care of the rest.
Mini goals keep me sane...But I never forget the bigger picture!