In my case it was mostly office PCs that might have important documents or spreadsheets on them. I've been working on a redundant, networked backup solution to serve the whole office, but realized that I was building a henhouse while the chickens were already running loose. So I ordered some USB hard drives just to make sure things were getting copied.

Maintaining a super basic (but regularly verified) hourly incremental backup system has spared the people who use those PCs a lot of grief, plus saved me time trying to recover lost data.