There's not much to the Ringflute (eBay link) that isn't in the subject line. It costs $39, is made of ABS plastic with ultrasonically welded seams and it was invented by James Johnson, who came up with the idea after, er, trying to demonstrate ocarina fingerings to a Chinese busker using a piece of hosepipe. You can find out more at ringflute.com, which includes this classic 'way to much reverb' sound clip. There's also a $500 wooden version, if you get into it...