I keep mine in Scrivener. I've set up my outline as file "scenes" in the program. I do all my drafting via an alphasmart Neo and once I finish a scene there, I upload it into its predetermined file. It keeps things organised and I'm ready for editing in December this way. Scriverner backups my story in the program and does a second backup into dropbox automatically. Once a week, I upload a zipped file of my manuscript onto a thumbdrive that hangs on the wall in my office.