Your typical white esky is a cheap way to keep drinks cold and food warm, but it's not very flexible. Its boxy shape is downright awkward compared to the Wunder Bundler -- an insulated blanket that can wrap up anything from a six-pack of beer to a stack of takeaway containers.
The $US25 price tag makes this a lot cheaper and more useful than that so-called "ultimate cooler". Made from waterproof materials, it's great for use as a dry seat on a wet outdoor surface, as an impromptu baby-changing pad, or a wrap for a wet swimsuit. The reflective material on the inside can even be used to signal for help in an emergency -- like, say, that time you drank six beers in the bush and got lost.
If they had Wunder Bundlers in The Hitchhiker's Guide to the Galaxy, you probably never would have been told to bring a towel. Don't leave home without it.