As of last night, Mac gamers (whoever they may be) no longer must feel like second class citizens of gaming because Valve has opened its arms and its digital distribution model, Steam. I downloaded the client this morning and once updated, was taken to the front page where a banner told me that Portal is FREE until May 24th as an added incentive to get your Mac steamy. But the wording is a little dubious – ‘Play Portal for free’ – which makes me think that the deal is more of a timed demo of the full game. Since the first-person puzzler can be completed in an afternoon, this isn’t necessarily a bad thing as you’ll have more than enough time to whiz through it. With new games being promised every Wednesday and an already meaty list of Mac compatible games available on Steam, it can’t hurt to sign up and see what all the fuss is about.