found this on hotukdeals.com ... guinness book of records is selling for £10 at whsmiths at the moment (half price) but if you print out this voucher
marketing.whsmith.co.uk/images/41/WHSmith_Sept09_Voucher_v2.pdf
you can get £5 off any £10 book or £5 off £15 stationary! Just been into whsmiths in birmingham and they had loads. Very cheap christmas pressie for nephew