An Apple technical note appears to suggest that iPod users this summer might consider wearing cotton and avoiding hyper-air-conditioned rooms when exercising. If not, be prepared for a shock.
According to the note Apple Earbuds and static electricity, users of any portable electronic device with earbuds can receive a "small electrostatic discharge from the headphones" in a place, indoors or outdoors, where the air is very dry.
To minimize the risks of electrostatic discharge from the headphones, avoid using the headphones in extremely dry environments or touch a grounded unpainted metal object before inserting the headphones. Static electricity can be controlled by a number of different methods.
Indoors Try raising the moisture level in the air of the local environment by using a portable humidifier or adjusting the humidity control on your air conditioner.
There are a number of anti-static sprays that can be sprayed into the air that can be used to reduce static.
If you have dry skin, try anti-static hand lotion.
Try wearing different clothes. Try clothes with natural fibers since synthetic fibers are more likely to hold a static charge.
Outdoors Try to keep your device out of the wind by using a case, or leaving it in your bag or pocket.
Avoid removing your device from your pockets frequently as rubbing the device on certain materials can cause a static build up.
Right, I'm sure that iPod users will wear antistatic wristbands to avoid a shock. I've never experienced this static phenomena, although I admit that I'm a schvitzer, who naturally raises the moisture level in my local environment. For once, this is useful!