Most people think of diamonds when they hear the word kite, but associate them with children.  This big kite from Premier Kites is definitely adult-sized, and unlike most diamonds does not need a tail in order to fly well.  It is playful, but a reliable flier.  It is well made from ripstop nylon and carbon spars for lightness, so can fly in very light wind.  There are several designs (some with fibreglass spars), but this particular one is, I think, no longer available.  See video 2 for others.  The list price (2011) is $43.95, which is very reasonable for a kite of this size and quality.  Try Cobra Kites, who usually have several design choices.