The famous game from Rovio is available for PC for free, just visit the TipsoTricks Facebook page. Click Like and you can get 2 setups, one is for Windows XP (in case of trouble you can apply these fixes), another is for Windows Vista/7.
Linux users can play it with Wine emulator reading this post.
Recently is available (still in beta) a version for Google Chrome that you can play for free at this address; you can choose betweend standard and high definition; this version has also some exclusive levels. You can try to run the app also on other modern browsers.
There is also a Flash version playable here.
To follow all the news about Angry Birds game you can visit Angrybirdnest site.
There are various other similar games, you can find a list of best clones in this my previous post.
Angry Birds free for PC, Linux, Google Chrome and online play by Simo Blog