Todays Daily Star has an offer for a free Giant New Moon (Twilight) poster worth £7.99. Use the online link to pay £2.49 postage, or you can send an A3 stamped addressed envelope (with £1.08 postage stamps on it) to Daily Star Reader Offers, PO Box 2006, DEPT TLP, Aldershott, Hampshire, GU11 9WB, or fill out the coupon in the paper and send with a cheque or postal order for £2.49 to the same address.
As my daughter is Twilight mad, £2.49 isn't bad for a poster, but seems a lot for just postage! £1.08 with the SAE makes it a cheaper alternative, but more fiddly. Makes a cheap stocking filler present for Twilight fans though.
No end date but I would imagine stocks wont last forever.