With web applications, this question is significantly harder to answer. Assuming they're using files on a desktop computer, find a magic backup or sync product

With web applications, this question is significantly harder to answer. Assuming they're using files on a desktop computer, find a magic backup or sync product. They all have pros and cons. I used to develop Syncplicity. It could backup "My Documents" and "Desktop" automatically, but you still had to manually add folders outside of those defaults. It was useful for a "magic backup" of things that could upload and download easily; but it wasn't going to just snapshot an entire computer. If you want to snapshot an entire computer, a lot of posts in the thread recommend Time Machine for Mac. Just understand the tradeoffs: Do you want to snapshot the entire computer, but you don't care about "cloud" features? Do you want "cloud" features like sharing, backup even when you're not home, but you don't care about restoring a computer to an exact point in time?