The first full week in August brings a downloadable expansion and a WWII strategy game to PC gamers:

Fallout 3: Mothership Zeta: In the fifth (and final?) downloadable expansion for Bethesda Softworks' post-apocalyptic RPG, you character finds a smashed spaceship and finds himself beams into orbit aboard an alien mothership. Look for new weapons and, yes, aliens to shoot with them.