If a required activity is what's causing the boredom, an easy way to cure it is to try doodling on a piece of paper. This can help to keep a person focused on the activity at hand and prevent daydreaming when it's necessary to pay attention. Also, if a person is bored and lacks focus, he should move away from or shut out any background noise, which creates slight disinterest.
If boredom creeps in because there's nothing to do, try making a game out of mundane chores. Play against others online for completing tasks such as household chores or exercising.
Another idea for something to do when bored is to get up and move around or go to a different location. This could be as simple as taking a walk around the block or to a local coffee shop. If something more adventurous is desired, try going on a long, scenic drive in a previously unexplored part of town.
If the problem is a demanding or repetitive chore, try taking several 2-minute "mental" breaks at regular intervals. A mental break doesn't require a person to go anywhere, it's just a way to stop and relax the eyes and mind momentarily. This can help to increase focus when the activity is restarted.