The listing, STALKER: Shadow of Chernobyl (PC) Steam Gift has ended.
I've got an extra copy of S.T.A.L.K.E.R.: Shadow of Chernobyl to gift to a lucky steam member up for auction.
You can also check out it's page for info:
http://store.steampowered.com/app/4500
Of course you'll need a steam account and when you win the auction, I'll need either the email address connected to the account or your steam account name so I can send you the game directly though steam.
Obviously there's no shipping as it's digital content. The included pic is a screenshot of my account with the game sitting the in the 'gifts' section to prove I have it.