prevent second hard-drive from spinning up after standby I have a MacBook Pro with two harddrives, an SSD in the main slot and a larger, normal drive in place of the superdrive.

Because of power consumption and noise I managed to get my Mac to not automatically start and mount the second harddrive when booting up, but it still spins up the drive when waking up from hibernation / standby / sleep (don't know the correct terminology here). 

Is there a way to prevent this? I have a script that ejects the disk, causing it to spin down. I guess I am looking for a postWakeup-hook of some sort to run it when the laptop wakes up.

Any advice would be appreciated.
Running your script on wake up, with Power Manager, or using SleepWatcher, for instance, should do the trick.

There are, actually, different sleep modes, and knowing exactly which one you are using may help too, as Sleeping your Mac should not use the Hard Drive, the second disk should stay idle. Here is a brief explanation of what happens with each sleeping mode.