I just made something for myself that I think could be useful to someone else.
I already backup my raspi's installations with https://github.com/lzkelley/bkup_rpimage, but you cannot easily manage 4GB files (even if sparse) to make cloud backups, so in case my local disks explode, I also need an off-site disaster recovery option.
Thus I need a small enough backup to reboot my system with the least work possible.
I have to backup only the "sensitive" files (home, apache configs, mysql database, crontabs... in my case, but you might have more in mind), zip them, encrypt them because who wants to put on the cloud stuff which is in the clear, and then upload to dropbox, with no intervention on my part.
I share because I want to give back to the community I learnt much from, and also because I hope that you nice people who are better than me at scripting can make a really powerful tool out of this initial attempt.