The same cloth you would clean glasses with.. There are also recommended cloth for them.
Blackberry Screen Wipes are a great product and will work perfectly on an iPod screen.
Lens Wipes Cleaning Towelettes are perfect for keeping your camera lens clean.
Laptop screen wipes are definitely worth buying. Not only do they clean fingerprints and other marks off of screens, they also do so safely and without damaging the delicate material of the screen.
Electronic cleaning wipes are used to clean an HDMI flat screen monitor. They have minimal moisture and use a cleaner which is safe for the screen's surface.
A sweeper with soft brush for the plastic and computer wipes for the screen.
Do not spray windex or any surface cleaner directly on the screen. It can drip and run in to the electronics. You can use products like Endust Electronics cleaner wipes to clean the screen and the casing.
Some general computer/tv screen wipes do the trick. Even not on the screen but removes fingerprints and dirt from the whole PSP. You can pick them up at a general hardware store for about £1/$1.
Baby wipes are made to be soft. They clean babies, so it seems logical you can use them to clean your hands.
with alcohol wipes
Several Nintendo authorized third parties sell cleaning wipes and fluid solutions for cleaning the Nintendo DS screen. According to Nintendo, a damp microfiber cloth with clean water is also an effective way to clean the screen.
The cleaning solution is specially formulated to use on these sensitive screens. The EZ Screen wipes are a two step process: a wet wipe is used to remove finger.
baby wipes