Today I was crazy enough to insert a DVD RAM into my Powerbook 12″, so I was completely unable to remove the disk, because it was not mounted anyhow, and pressing F12 didn’t work either. So I looked around and found this magic spell:

drutil tray eject

I store my personal documents in a 128bit encoded .dmg file, which is password protected (good old porns I finally faced the problem, that I’ve grown out this image - but i had no place to create a new one and copy over the contents (I was working heavy on a dvd edit) - so i RTFM.

hdiutil resize -size nn[m|g|t] mysecret.dmg