Mine came in my “Other stuff” packet along with a couple of Apple stickers and the CDs to reinstall OS X. Random!
If that doesn’t work, they sell “computer cleaning cloths” at stores like Target and Best Buy – I don’t know what kind of toxic stuff they are coated with but they are supposed to be computer-safe and nonstatic.
I use a mix of half isopropyl alcohol and distilled water. Mix it in a spray bottle and you have iKlear, which retails for about $20 for a 2 oz. bottle.
A soft hand towel is usually gentle enough to use. But never spray onto the screen! It could drip down into the video inverter board at the base of the display. Spray it on the towel first.
And for cleaning the white case of a Macbook, pencil erasers. Weird but it works great.
I use that reallly ridiculously expensive solution from iKlear, but it isn’t all too great, and definitely not worth the money…I’m looking into solutions like clear screen guards, like they have for cell phones. Stick a cheap one on, get a couple of fingerprints on it, peel it off and repeat….