Autodeleting resource forks on FAT disks
There are many ways to remove .DS_Store files; it really depends on what your exact needs are for the method you decide to use. To automatically remove them when you login/logout would be quite different from ejecting a disk, since it's a completely different process. You can disallow .DS_store for from being allowed to write to network disks, etc. by opening up Terminal and entering:

defaults write com.apple.desktopservices DSDontWriteNetworkStores true


to manually remove already present .DS_Store files you can use:

dot_clean /path/folder


which merges any such files with the parent file.