I do all my writing on the computer. I haven't done anything hand-written since high school, approximately 1995 or so. Printers got inexpensive enough that even as a teenager, I could afford one and was able to get all my notes printed at home. Beats the hell out of smudgy notes on notebook paper, not to mention that keeping up with notes from session to session is far easier.
My maps, I use more of a mix. I do my overland maps and city maps in Photoshop. For dungeons, I typically do hand-written maps on graph paper just because it's still faster and easier than designing on the computer on the fly. After I play, I typically do the maps in photoshop, autorealm, or campaign cartographer 3 if I want to use them again or show them to others.