Losing your work just got a whole lot more difficult! I've written a script that will automatically save your map to a subdirectory in your maps folder named "autosaves", every X minutes that you define.
To make things easy, I've assembled instructions, the download, and a more detailed description in my Archive Thread, so head over there to grab the script :)
Unfortunately, I can't add an anchor to the link, so you'll have to find it in the list. To ease your searching, it's the first under "CubeScript Creations" >> "Scripts". (You can always just search with Ctrl+F too :P)
Hope the script is useful, and that people enjoy it :) Cheers.