This Apple Knowledge Base article explains how to prevent OS X from creating new .DS_Store files when opening folders on remote volumes mounted using SMB/CIFS, AFP, NFS, and WebDAV. I particularly find these files to be annoying when browsing SMB shares on my Windows box. This is also helpful for network administrators who also maintain Macs as these files are not scattered around the network. Granted, they are not large files, but they are still bothersome and could possibly confuse Windows users.
To prevent the creation of these files, open the Terminal and type:

defaults write com.apple.desktopservices DSDontWriteNetworkStores true

Once you restart the machine, these settings will take effect.
Note that this does NOT disable the creation of local .DS_Store files.