Mac Tip: Avoiding .ds_store creation on your network drives
From this item at macosxhints – Prevent .ds_store creation across multiple user accounts
it turns out its fairly easy to configure an OS X client to apply the setting for any user who logs in.You just need to run this command…
defaults write com.apple.desktopservices DSDontWriteNetworkStores true
…under a single account, then copy the created plist to /Library/Prefrences.
The article also has other ways of going about this, including vetoing files on the samba share directly (clever!)