If you really can spot a face in the crowd, you could be a valuable asset to national security. Scientists are seeking 'super recognisers' - people who can spot a fake passport for instance, or find a criminal on CCTV.
Very few people have the skill - and it's not something you can be taught. To find out if you're one of the special few, take a look at Sally Simmonds' report.
Click here if you think you are a 'super recogniser'.