I didn't make big projects yet but I always have some group, a backup in the computer.
I have two external hard drives with backups. And sometimes my flash drive with a latest backup when I have hours of work...
e-mail, I don't use... But I though of using FTP. (and access it on many computers on the world with Internet) xD
Omnicalc RestoreMem saved me 1 or 2 times.
But not always... It was just a little thing though.
@BuilderBoy: you are in a harsh school for calculator development.
@Iambian: what percentage of people have to hear the "No."?