Windows XP embedded supports a feature that is extremely user for mobile computers that use this mobile version of Windows called appropriately Hibernate once/ resume many (HORM). Every mobile user knows that hibernation on Windows XP based computers is extremely important for helping maximize battery life while allowing the mobile computer to wake up very quickly when needed. HORM allows the device to resume many times without having to hibernate over and over in a typical off and on mobile scenario and is very robust. MSDN has a great article and white paper explaining the concept and how developers can capitalize on this great feature.
(via Mike Hall)