Steam is now offering pre-purchase of Tomb Raider: Underworld through Valve's online service, and those who take advantage of this will receive a free copy of Tomb Raider: Legend to play in the meantime. This is not a buy-before-you-try deal for the next installment in the Tomb Raider series, however, as a playable demo is available. Word is: "For those who pre-purchase and already own Tomb Raider: Legend on Steam, you'll be able to give your free copy to a friend." In other Steam/Valve news, the Valve Complete Pack is now on sale (thanks jimnms), offering the entire Valve catalog (including Left 4 Dead) for $99.99, which is close to 60% off the cost of buying all those games individually. Update: GT points out Tomb Raider: Legend is also free via GameTap.