O.K., so I'm listening to commercial radio on the way home, and I hear an add for... DNA storage kits. Advertised for your "safety" and "just in case", this kit (unlike the one I link above, which is for posterity and personal curiosity) was playing on the fear of anyone who believes a disaster might befall them. Sick puppies those jerks are. Which is why I linked someone who's a little more responsible.
Maybe, just maybe, if you wanted to keep it around for identifications purposes for yourself -- if you lived alone and had no living relatives, and were afraid that if your body were stolen they couldn't identify it from the usual dental records that your dentist keeps. Say, you were dipped in acid or burned at an extraordinarily high temperature.
But this is what gets me. I can give you, right now, your own guaranteed DNA storage kit for free. Ready?
You've got it. It's your body. You store your own DNA. And, you store much of the same DNA as your relatives, enough so that making a match between you is quite easy. Plus, you're constantly keeping it up to date, and have billions of billions of cells to sample.
At some point, I have to put up the most aggregious example of fearmongering I found, just so I can get it out of my system. But as for this piece of crap, save your dough and use it to buy an ice cream, just to remind you life isn't what you see on TV.