GOG are selling a bunch of their DRM free games at 50% off.. though the one that interests me is Duke Nukem 3D Atomic Edition for $2.99 which works out at £1.90 or there abouts.
EDIT: Actually, it's £1.55 according to Paypal.
The other games - some at $4.99, some at $2.99 - are
ARCANUM: OF STEAMWORKS AND MAGICK OBSCURA
DUKE NUKEM 3D: ATOMIC EDITION
INCREDIBLE MACHINE MEGA PACK, THE
INTERSTATE ’76 ARSENAL, THE
JAGGED ALLIANCE 2
LONGEST JOURNEY, THE
MYST: MASTERPIECE EDITION
TEX MURPHY: UNDER A KILLING MOON