These are special cans you should be able to buy in any decent computer or electronics shops. The advantage of these cans over a vacuum cleaner is that it has a long, thin tube that concentrates the flow of air into a small stream and that you can easily fit in between your circuitry. The downside is that it blows away the dust, so you still have to pick it out in the end.

You can even use this can to clean the crums, skinflakes, and hairs from between the keys on your keyboard.

"The Large Print giveth, and the Small Print taketh away" - Tom Waits