How's your brain feeling these days? Sluggish? Not quite as sharp as it used to be?
Take a look at Lumosity -- a really cool Web 2.0 site that uses games and puzzles to get that mind honed back to razor sharpness. You track your progress through 30 levels using about 10 psychologist-tested puzzles to keep you interested and focused.
It's currently in beta, and it's free (for now), so click through and get your brain choppin' some wood.