.DS_Store (Desktop Services Store) is a hidden file created by Mac OS X to store custom attributes of a folder such as the position of icons or the choice of a background image.
By default, the Mac OS X Finder will create a .DS_Store file in every folder that it accesses, even folders on remote systems (for example, folders shared over an SMB or AFP connection).
These .DS_Store files can be really pesky in a multi-platform network environment, they can basically just lead to unnecessary filesystem clutter that Windows & Linux users receive no benefit from.
This application can be used to delete .DS_Store files.
You can also optionally delete Thumbs.db files.