I remember watching the "Tonight Show" years ago (the first time Jay Leno was the host) when a scientist was on showing what he thought was happening in the Burmuda Triangle--and it was this theory. He showed it using a large body of water in plexiglass and pumping methane into it. The toy boat sank like a rock and the model airplane burst into flames (I believe).

While I can not remember how plausible the scientist's credentials were, I thought it was an interesting segment.

At the zoo I volunteer at, for a while we had what were called "rainbow jellies", and when the light from above their tank shone through them, their whole body looked like the tentacles of this one. It was incredibly cool.

The ones we had were similar to this one: http://4.bp.blogspot.com/_0LlKkQ7nRJI/RzHGuYZXfnI/AAAAAAAAAoU/-UVEc4kUzXE/s400/periphylla48_500.jpg
but were much cooler looking.