The Tangle serves no useful purpose whatsoever, so as far as we're concerned it's indispensable. An extended infinity loop of curved metal bars and a little restlessness are all you need to keep you occupied for hours. Twisting this tactile toy into myriad shapes is one of life's unexplainable little joys, and of course it's also hefty enough to act as a paper-weight. Worry beads for the 21st Century - you won't be able to put it down.