Have you heard of Turkish Stretchy Ice Cream, called Salep Dondurma? It's fascinating stuff, and Dave Arnold has come up with a pretty good - and legal - way to make it in the US. The authentic ice cream is made with salep, a flour ground from the tubers of wild orchids that only grow in Turkey. The Turkish government does not allow the stuff to be exported so you can't legally get your hands on it in America. However, if you combine the right thickener with the right hydrocolloid, you can pretty much replicate the texture of Salep Dondurma.
Check out a YouTube video discussing the stuff here
but if you want to find out how to make it in the US, read the post on Cooking Issues