[WanderingMinstrel]

I've been using an app called MobIsleNotes (search Market) that has a backup function built in. Backs up automatically on start and exit, also allows manual backups to SD. Starts notes in checklist (to do) or plain text form. It's a little primitive compared to the MS note programs I'm more used to using but it might work for you. There's also a pay Pro version that could possibly do even more.