I wanted to get rid of safe sleep, aka hibernation on my new macbook air (MC665/AMC965LL/A)
Apparently they make a few programs that do this for you, but they do not remove the large safesleep file, they only disable the sleep mode.
To disable safe sleep mode: sudo pmset hibernatemode 0
To remove the sleep image file: sudo rm -rf /var/vm/sleepimage
It’s as easy as that, and with the Lion auto save and resume feature, there really is no need to waste that much SSD space! Make sure to not let your laptop battery die either!