WIREDGOV

Commuters could be in with a chance of winning a range of top prizes if they can find the 75 Underground stations hidden in visual clues in this poster.

The 'Look for Longer' competition, devised by the outdoor media owner CBS Outdoor, encourages lateral thinking and tests passengers' knowledge of the Capital as they travel around the Tube network.

Answers can be entered at www.lookforlonger.com and prizes range from iPads and Kindle Fires to a full Virgin Media VIP entertainment package worth £1,000.

The poster will be displayed over the next four weeks at more than 30 Underground stations including Canary Wharf, Euston and Oxford Circus.

With WiFi now available at Tube platforms, passengers can play and submit answers online while they wait for their train.

Simon Harrington, Marketing Director at CBS Outdoor UK, said: 'We wanted to create a campaign that would generate curiosity, intrigue and interaction.

'The three-minute dwell time on platforms, coupled with WiFi connectivity, not only provides the perfect environment for advertisers to reach a highly responsive audience, but it also offers extended engagement - that is to say the audience do something as a result of seeing it, be that playing the game, or sharing it with friends through social media.'

Participants have until November 11 to enter at www.lookforlonger.com.

To ask for help, use the Twitter hashtag #lookforlonger.