To use tabs, not spaces, for indentation: the argument no one raises.
Actually, in environments where editors like vi are the only ones available, it can be a nicer experience to use tabs to indent blocks due to the poor handling of multiple space indents in, for example, the "standard" editions of vi. And if you've ever had to share an office with someone whacking the space bar to do their indents, you'd be a rabid tab advocate by now, too!
-- PaulBoddie - 19 Nov 2001