There's lots of stuff like that out there, I'm talking about something I can actually replace the rm binary with, a wrapper that precisely maintains the rm interface as described here: http://developer.apple.com/library/mac/#documentation/Darwin...

I like the idea of actually wrapping the unlink syscall, but I have no idea if/how darwin allows that.

You can alias trash-cli over rm, though it ignores -i, -r and -f and instead runs recursively, forced and non-interactively by default.