Just incase this hadnt been posted, was bored and wanted some free stuff, so found these. (graphics card dependant)

http://steampowered.com/nvidia/
http://www.steampowered.com/ati_offer1a/

Seems lost coast is selling for £5.99 and Deathmatch for £2.99.

Nvidia = demo of Portal.
ATI = Halflife discounts.

If this has been posted before then my apologies, if not then some poor soul may find this useful.

portal: first slice has since been made available for all users free of charge. look in the steam game demo section for DL.

im not sure about the half-life offers current status, but i have both games, and didnt pay for them or sign up for this offer. maybe i got them with orange box

AFAIK, Lost Coast comes with any purchase of HL2, which would include the Orange Box (which is amazing value, Portal FTW!).

Orange Box gets you HL2, HL2 Ep1, HL2 Ep2, Portal, Team Fortress 2 and the Lost Coast tech demo.