to show hidden files, you'll notice that .DS_Store files are literally everywhere in Mac OS X. Although there's nothing harmful about these files, seeing them in every single folder in Finder can get rather annoying (especially when you see a .DS_Store file on your desktop). If you just want to get rid of all these seemingly extraneous files, then there's an easy solution for you.
LATEST UPDATE (November 17, 2012): Asepsis does not work on Mountain Lion. Sorry!
Install Asepsis to make sure that you never see another .DS_Store file ever again. Asepsis is a system tweak that automatically redirects all new .DS_Store files to a special folder, out of sight and out of mind.
Finder automatically creates .DS_Store files to store display information, such as the position and arrangement of files in your Finder window. With Asepsis, Finder can still use .DS_Store files to store metadata, but you don't have to keep looking at them. Everybody wins.
NOTE: Asepsis will not remove any .DS_Store files that have already been created. However, if you delete a .DS_Store file from a folder, it won't reappear in that folder anymore.