You sign up, they give you an On The House game every month or so(?). Since Titanfall I've had Dead Space and Plants vs Zombies. Once downloaded they're yours for keeps.
Ha. Just looked and I've got Dead Space 3 and Battlefield 3 on Origin but not on Steam. Pity they're probably not games I'll ever get 'round to playing.
this week on steam 'little street racing' and 'real world racing' are on specials for a few quid each, both are 'overhead view' racers. me and a couple of mates decided we need a fun knockabout multiplayer racer and ended up getting both.
real world racing is a bit more of an attempt at a sim, it may have more legs in singleplayer but the multiplayer was a little more dull (at least with initial cars available)- it was ok just tracks were too 'realistic' and races just got stretched out.
little street racers is much more like the games of yore, twisty tracks and slippy slappy handling and gameplay. would recommend this is the better option for multiplayer anyway.
i bought the 4-pack for 'real world racing' though, so have a spare 'gift' if anyone is interested
There's one per week; The Humble Weekly Bundle, plus the standard Humble Bundles every month or so. And the Humble Book Bundles. Not to mention the Humble Store.
Bundle Stars is picking up steam (ho ho) now, too. I'd be all over that 2K one if I hadn't recently bought Spec Ops. At very least I'll be chucking the charity a dollar.