Do you know any other hook-less angling techniques?

Apart from fishing with a camera for underwater trophy shots, what other ways of hook-less fishing do you know where you can still get a thrill of action? A quick google search returned hook-less fly fishing, or as I experienced myself this year, fishing for garfish by using a bit of silky thread - it works a treat apparently by snaring the sharp teeth among the fine twine. Hybrid angling worked as well: sometimes without a hook, sometimes with.