A healthy body is a healthy mind

Most people know that a half hour of exercise per day will help you become more healthy and alert. Most people also understand that a healthy body is a healthy mind. This is because people who keep themselves fit and active have good circulation (important for feeding nutrients and oxygen to the brain), good cell regeneration (which aids in memory) and the ability to sleep better at night (one of the most important factors in brain power).
However, an interesting, lesser known fact is that different parts of the body are controlled by different parts of the brain. By activating body parts which you don't pro-actively use in your day-to-day life can have a dramatic effect on your brain and your IQ.

1. Righty-lefty

By switching to your non-dominant hand you are forcing your brain to start thinking about how to do things and emulate your dominant hand. This will open up the opposite hemisphere of the brain and you'll soon notice a difference. Not only this but you'll be able to juggle better too!

2. Read upside down

Read the new Harry Potter book? Try reading it upside down! This will be slow and difficult at first, since essentially you're learning to read again (with a new set of characters) but over time you will become proficient and can impress your friends with your new upside-down reading ability! Strictly speaking this isn't a body part, it's more of a cognitive ability.

3. Feet 'n' toes

A common characteristic of intelligent people the world over is that they are often very dexterous and flexible. Often they will be ambidextrous (use both hands equally) and use their feet to pick things up, turn on light switches etc. By using your feet more often you focus your brain to force on a new body function and increase spatial awareness.

4. Pick up 'n' play

Learning a musical instrument like the guitar or the piano can drastically increase your intelligence, and sometimes in a startlingly short amount of time. Again, you're learning something new and experimenting with your fingers, opening up new parts of your mind.

"I think I should have no other mortal wants, if I could always have plenty of music. It seems to infuse strength into my limbs and ideas into my brain. Life seems to go on without effort, when I am filled with music."
George Eliot (1819 - 1880)