From the link: "ODEON is the first UK cinema chain to team up with Facebook Deals. When you ‘check in’ to a participating ODEON (using your smartphone) on Facebook Places, you’ll receive a free small popcorn.
Just ‘check in’ to get a voucher on your smartphone’s screen and show it to an ODEON cashier. There are 1,000 small popcorns available across 20 ODEON cinemas and the offer ends when stocks run out or on 31st March 2011."
Participating ODEON Cinemas are Metrocentre, Trafford Centre, Liverpool One, Manchester Printworks, Brighton, Kingston, Guildford, Leicester Square, Norwich, West End, Silverlink, Colchester, Cardiff, Southampton, Braehead, Bath, Tunbridge Wells, Glasgow Quay, Uxbridge, Lincoln.http://www.facebook.com/notes/odeon-cinemas/odeon-facebook-deals/205809226100940