It sounds like a cat choking on a hairball, but it'll help you increase your know-how! The standard (most popular) typeset is QWERTY, which came into standardization with the first typewriters (*interesting side fact that has nothing to do with this article whatsoever: "Typewriter" is the longest word you can make using only letters from the top run of your keyboard?). QWERTY is an arrangement of keys that was actually designed to slow typists down! This was because typewriters were notoriously erratic and often broke down due to people typing too fast. And so in an ironic twist of fate the most popular typeset is in fact the most inefficient one! DVORAK is one of the more efficient ones, in fact for every mile that your fingers travel on a DVORAK keyboard, they'd have traveled 4 miles on a standard QWERTY keyboard! So- learn to type faster AND increase your intelligence while doing so.
How to switch your keyboard to DVORAK and more from mwbrooks.com
All about DVORAK at Wikipedia.org
2. Cubic Cognitive Comprehension
The most misspelled (*interesting fact that has nothing to do with this article whatsoever no. 2: Misspelled is also one of the top misspelled words in the English language!) puzzle in history, Rubik's Cube was invented in the 70's by a Hungarian architect and is said to be the most sold toy in the world! It's also one of the best for getting your gray matter going. You're bound to know someone who has one stored away in a deep dark box, or thrown behind the sofa in a moment of profound frustration. If not, pick one up at your local toy store for pennies and get shuffling!
3. Sodiku.. Sodak..Sudako..Sod it!
The word sudoku derives from the Japanese phrase "Sūji wa dokushin ni kagiru," which means "the numbers must be single," or "the numbers must occur only one.". Sudoku is a great and popular puzzle because the rules are so simple yet the methods to solve it can be extremely difficult. Sudokus range from easy to fiendishly difficult and there are many different kinds to try out once you get bored of the standard version.
At WebSudoku.com you can start playing immediately (for free) and adjust the difficulty too.
*Additional note: You can actually buy Sudoku themed Rubik's cubes, thus you can kill two birds with one stone!
4. Juggle your way to smarts
The left hemisphere of your brain controls your right hand and the right hemisphere of your brain controls your left hand. This means that by using your less dominant hand you are stimulating the opposite half of your brain. This is a common phenomena which explains why ambidextrous people are often more intelligent. Taking up juggling is not only a good way to show off to your friends but it will wake up parts of your mind.
WikiHow has a good guide to get you started playing with your balls (sorry couldn't resist that one).