I use beersmith. I add everything that I can't change or modify to the notes field. To be careful not to lose anything, I copy my beersmith folder to three, separate, external hard drives, a USB drive (I keep on my key chain), and my parents computer (about 120 miles away, through remote software (teamviewer)), any time I make a change. It seems like overkill, but I use the external hard drives to store different things, along with the USB drive. <20 MG of space doesn't seem like much to 'waste' as a backup when the smallest drive is 250 GB and the USB drive is 8 GB. The drive on my parents' computer is also a drive I set up to automatically backup their stuff (pictures, email, etc) so it's not much to stick mine on there as well, for off site storage. I also unplug the 250 GB drive whenever I am not actively changing files on it. The other drives seem to shut down when not in use, but this insures that I am 100% sure, at least 1 drive is not running unless in use. This is for mechanical failure. The USB drive is also unlikely to die from mechanical failure. This may seem like overkill, but I'm already doing the same with things like my pictures and other important documents. So what is <20 MB worth of additional space.
I keep my beersmith in a Dropbox folder. I can access it from any of my computers.
Oh I do that as well. Forgot about that one. Wow, I feel like I'm a little paranoid about losing things now. I also just got another 2 TB that for the moment is going to be like my 250 GB and only be plugged in to back up things. I don't really need the space yet, but it was super cheap, and I have things I'd like to have backed up that would fill up the 250 GB. So it will be; original files, dropbox (what will fit), 4 external hard drives, jump drive (what will fit), and my parent's computer (main drive and their external) for offsite. My parents almost lost about 10 years worth of digital pictures though. I had recently backed them up to one of my hard drives, so they didn't lose them, but it makes me feel justified in my over zealousness. I also regularly back up their important files to the same places I put mine.
I am a firm believer in having an external hard drive to use for nothing but backing up. That should be its only use and the only time it should be plugged in is when actively transferring files. I've seen too many people lose important files and almost saw my parents lose 10 years worth of photos. Disconnecting it when not in use helps prevent mechanical failure of the drive and extend its life. USB drives are cheap as well and I think everyone should have one of those to back up anything that is smaller (not big picture collections, etc). I put my taxes (encrypted), gnucash files (again, encrypted), beersmith folder, some of my most important pictures, and etc on there. At minimum this gives you 1 backup for bigger files/collections and 2 backups for smaller things. Both of which should be fairly well protected from mechanical failure (rarely plugged in and not mechanical in nature).