I'll join in the handpowered lawnmover crowd ... and yes, I mostly work on the computer and I do it because its such a great tool to work with, undo, layers, textures, filters a lot of stuff to play with to get the look you want. And mearrin also raises a very good point - hand drawn doesn't equal pencils, pens and so forth - you can hand draw with a tablet too... and you hand draw with a mouse too if you use the free hand tools (its just not as easy)

The important stuff is to make some great maps, and I personally ain't finished with the old fashioned tools yet