The sad old operating system that is OSX has an annoying habit of littering hard drives with .DS_store files, and it even does this on network drives from other, non-OSX machines; these cause occasional stumbles in RSync operations, and also just get in the way and annoy the heck out of me. Finally I was bugged enough to find a solution. If you log in to the Mac with admin privileges and type this in a terminal:

defaults write com.apple.desktopservices DSDontWriteNetworkStores true

then restart the Mac, the behaviour appears to be prevented. I haven't found a way to stop the Mac from doing it on the local drive, though.

Now if only I could find a way to make the menu and dialog boxes for every application show up on the same monitor that the application happens to be running on...