I'm either lucky or cursed with a sharp memory. If I have a story idea while driving or whatever, I can remember it and put it down later on computer.
My touch typing is quite good, and when I write, the words flow directly from my brain to the screen. I free-associate, then save rough text in temporary files.
Computers being what they are nowdays, I can save hundreds of files and check back on them later. I organize everything by folders, so ideas for one story or novel go into that folder. I also have general folders "horror", "mystery" etc.
In high school I took typing and maybe that one course was the most beneficial to me of the otherwise forgettable 4 years.
Working for a newspaper makes it necessary to type, and I remember vividly those huge old clunky Underwood manual typewriters on the desks, all clacking away. Noisy but not as much as the Linotype room, which was chaos!
Having a technical background as well as literary, I worked with computers for many years, and so they are 2nd nature to me.
When I sell my novel I'm gonna buy a nice Dell handheld that interprets handwriting via stylus, but for now, I rely on the ol' grey matter for my quick idea storage.