You can clean your ipod screen this way
.
1) The first step is to turn off your iPod touch. And if hot, from processes let cool for 5-10 minutes.
2) Take your iPod out of its case
3) Place on a paper towel
4) Get another paper towel and fold until at least somewhere at 2x2 inches long
5) Get a towel (cloth only!), preferrably small, and just place it next to the paper towel that your iPod is sitting on.
6) Wet the folded paper towel, and squeeze out the excess water
7) Apply the wet towel on your iPod hard, to get any grease or etc. off. (back and front), and make sure not to get inside any of the iPod's parts.
8) Also, you may want to use a special cloth that is specifically designed to clean glass.
9) Once wetting, immediately take your towel (cloth), and wrap it around your iPod. Also dry your iPod, thoroughly.
10) Once done wipe your case with the towel (cloth), to make sure you get ALL of the grease or etc. off. I wouldn't really wet your case because it might ruin the texture or its color.
11) Put your iPod back in its case.
12) Take a look at your new and improved iPod!