Guys, can't we make a multi-level swimming pool? Like, separate it in two planes horizontally and have a glass-enclosed glowstone-lit "lounge" area in the middle, accessible via a glass-enclosed staircase on one or all sides? It'd be far more fun than just a swimming pool :(

The glass-enclosed bit could even be only accessible from inside the pool, mysteriously floating in the middle of it. Let me hear you say "ooooh!"

I think someone (drew) should make a submarine

with a hatch in the bottom, and air inside

Thank you Caer, I now feel proud of my idea.

So secret underwater/underlava layer it is then. I reckon we should build stuff first, then flood the place otherwise it'll become a lil' difficult. Why did Notch remove the usefulness of sponges? :-@