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My brother uses the black cloth that came with his Mac, since that is a bigger size than the one that comes with the Touch/iPhones.
 
I'm surprised the iPhone 4 didn't have a cleaning cloth, or was that just me? I also ended using the Mac. But any wipes that come with glasses (if you know someone who wears them) work as well.
 
For all my electronics, I use MicroFiber cloths that I get drom Dollar Tree and iKlear which I got from apple.com.
 
Hell, go to Wally World where you can buy 5 micro fiber rags for $5 then go to their vision center and buy a bottle of lens cleaner for $2. You can bring back the empty bottle of lens cleaner as many time as you like and get free refills. Been using both for over a year and works great.
 
When a smudge gets in the way, I swipe my finger over it to change it. I might use my shirt if it's bad, but that just pushes the smudges around. The only effective thing is the microfiber cloth that came with my various pairs of glasses and sunglasses.
 
Cleaning iPhone

I use a large microfiber cloth we got from Costco and a little spray eyeglass cleaner when necessary. Works great.

Oh yeah, look for the blue ones. They are softer and better than the yellow ones. Either of them are better than what come with the macs.
 
Microfiber cloth that came with Samsung TV.
If I don't have it by me I'll just use the softest thing in arms reach.
 
I wash using the washing machine but it made a lot of noise so I switched to the dishwasher and it works great. I have a very clean phone.
 
I've noticed occasionally, "crud" builds up in the speaker and mic ports (I've a 3G) when it is in my pockets. I use a toothpick to gently clear it out.
 
I use the cloth that came with my eyeglasses. It's supposed to be able co clean glass surfaces pretty well.
 
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A small, blue microfiber cloth I got from Wally World. Sometimes I dampen with a few drops of water.
 
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