Just checked and it's already enabled... only seems to work when I physically move a file around, then it'll snap to the grid, but not when I extract files.
go here: HD>System>CoreServices. find ArchiveUtility, open it. in preferences, set it to delete archive after expanding (there are some other useful options as well)...
go here: HD>System>CoreServices. find ArchiveUtility, open it. in preferences, set it to delete archive after expanding (there are some other useful options as well)...