Hibernation: Unexpected Shutdown Or Reboot

I've just been using my computer (XP) and have lots of applications running, taking up a lot of memory, even when minimized. Then it hit me - why not (probably in an upcoming version of windows) have an extra button near minimize/maximise, that puts the application into hibernation? The idea being that if the application needs no interaction, like possibly you are writing a word document, but you are waiting for some information to put in it via email. In this case, you don't really want to close word, as the email may arrive at any time. On the other hand, you aren't using word, so it is running in the background, taking up resources.

Why not make it so that when you click the 'Hibernate Application' button next to minimize, it minimizes the application, and writes the active memory onto the HDD. Then when it is restored, load it back out of the HDD into the RAM (much like the way the Hibernate Windows feature works). Certain applications won't be ideal for this, such as if you hibernated an mp3 player, it would result in stopping playback. But for other uses, this seems an excellent feature. It could even be expanded to restore individual applications to their working state after a full reboot (the applications would be there when you logon). This would safegard against losing your minimized word documents that you have open, if there is an upexpected shutdown or reboot. I understand that there is some optimisation going on when you minimize applications anyway, but I'm talking about total hibernation.