Drawing maps using a pen??!

ok so i recently got a x220t and now trying to find some stuff to do with it when making maps easier immidietly came into mind.
has any1 thought of a way to simply draw maps?? or use some kind of program and then export it to vmf?? would be sick.

You could draw terrain with it using 3rd party tools I guess.
But I don’t see much use in drawing other than sketching the layout or props you are gonna model.

Google Sketchup might support the pen. And there are tools to turn sketchup maps into vmf files.