That's an odd logo. What is it?

On Ryan's birthday in November 2005 (shortly before we launched the http://simplepie.org website), Ryan's co-workers decided to decorate his cubicle workspace with streamers and balloons. A month later, all that was left was a single green balloon that had been very slowly leaking air for the past 32 days laying on its side. Ryan had been trying to come up with an idea for a logo for SimplePie, and happened to glance at the last remaining balloon. He liked the shape, and as long as he removed the part of the balloon where you tie the bottom to keep the air in, it might be something cool. So he launched Macromedia Fireworks 2004, and an hour later he had the SimplePie logo.