There is a fairly large collection of Quartz Compositions stored in /System/Library/Compostions, including all those used for iChat, Photo Booth, iTunes Visualizers, and iMovie Effects. Many of them have no apparent purpose in any of the above, and yet, are fully compatible with iChat and Photo Booth if it weren't for the presence of a couple of hidden flags.

The innovation in Apple’s “Safe Sleep” is that it goes ahead and writes out the disk image, but then suspends to RAM. If you just resume, everything’s already in RAM and you can avoid the delay from resuming the image. If you lose power (or change battery), then it resumes from the disk image. By comparison, Windows offers both suspend-to-RAM and suspend-to-disk, but not at the same time.

You can change the Mac’s hibernate behavior using pmset; here’s the reference for it:

WxMac Issues