Today I contributed to science! I put on some freaky brainwave monitoring thing that looked like a headcrab, put on some other wired things and crap and then, I contributed to science in the best way I know how:
I played Tetris.
And how have you contributed to science lately?
I must point out; this doesn't have to be formal experiments you've taken part in! Maybe you combined two things together and suddenly they are more awesome - synergy!