Even Valve is in on the celebration, declaring Portal free to anyone and everyone, Windows or Mac user, until May 24th. That is awfully generous of them. As on of the few games I actually want to play on Mac, Portal was a welcome substitution for day 1 Team Fortress 2 support on the Apple platform.
Unfortunately, my Portal is completely broken. My screen is awash with white and I can see nothing, much less properly place a portal. I certainly hope this will be fixed soon, but until then, you can see that I've added my thought on the Game Revolution Daily Manifesto blog(y type thing). Here's a link: http://www.gamerevolution.com/manifesto/view.php?id=1005
If you don't feel like commenting there, please do so here! All quips about my choice of platform are warmly welcomed.