Now this is not particularly new. I can find references to it from 2009 and admit I made no effort to look back further. It is new to me and I'm sure many have yet to hear of it or try it. At first I was amused. Then hooked. This is fun! and takes focus if one wants a neat result. Hence the "zen" in the name, as it becomes a way to meditate, focus and relax. Zentangle takes doodling to an entirely new level. Creating tangles can even leave you with a free form drawing worth hanging on your wall or a way to decorate a pair of shoes. Whatever you do with it, you are sure to enjoy it!
You can find information on youtube (of course) and on the web. Just know that the word Zentangle has been patented, so giving credit where credit is certainly due - check out these links!