Once, on a Monday, April 24, 2006, I thought...
(And that is why it crashes a lot too: cuz they took lots of shortcuts ;))
These following few are the ones I remembered from my Win3.1 and MS-DOS's Edit program endeavours, which surprisingly still work in 2k/XP.
Ctrl + Esc : Opens the Start Menu (Useful if you don't have the Start Key on your keyboard. In Win3.1 it used to open the Program Manager's Task List)
Ctrl + Shift + Esc : Opens the TaskManager.
Shift + Ins : Paste (i.e. Ctrl + V)
Shift + Del : Cut (i.e. Ctrl + X)
Ctrl + Ins : Copy (i.e. Ctrl + C)
F10 : Opens the Menu (i.e. Alt. So Alt + F becomes F10 + F etc etc.)
Some of the few I've quite forgotten.
Rest of them are all listed on this page by some guy. And I'm pretty sure Microsoft must have some help file on it. Basically it's the control's behaviour which each application inherits so no biggie.