Most people have used cotton swabs to get in between the keys of their keyboard, but why waste them? You can grab a pair of disposable wooden chopsticks, wrap a bit of paper towel around the end, and get into the same small spaces.
Unplggd turned us on to this tip. Tear off a small piece of paper towel and secure it to the smaller end of a chopstick with a rubber band or hair elastic. Dab it with alcohol if you need to, otherwise just use the covered end to get in between keys on a keyboard, under the analogue stick of a game controller, or anywhere else dust lurks.
Just pull off the paper towel bit when its too dirty, add another, put the rubber band back on, and go back to cleaning. It's a great way to make use of disposable chopsticks if you're not eating with them, and you can get lots of cleaning done with one or two chopsticks. At the same time, you could eat greasy food with chopsticks to avoid dirtying up your keyboard in the first place.