hahahahahahahahahahahaha I agree, it makes quiet a bit of noise at night but I'm downloading BT torrents so it's ok I guess.
Someone was working on a custom firmware to spin down the hard-drive or set it in idle when it's not used.
In order to do so you would have to download linux and know basic programing.
People who make custom firmware don't share it with the rest of the community, they might give you the source code but like I said you need linux to make it happen.