3 things currently; some fun toys..
Web based two player bingo race game in an attempt to drag significant other away from mobile phone. :p
Optimised gravity sim, everyone loves a good gravity sim. Event driven physics and aiming for 10000 spheres at 60fps.
Alife simulation where critters can read and write symbols into/from their environment to see if we can't get some kind of rudimentary communication evolved.
Nothing super serious, but fun gadgets to tinker with :)