Keep in mind that if you no longer want to give Sony money, you'll have to stop buying/using a number of products.
Beyond Playstation, this includes Blu-ray, movies (Sony owns Columbia Tristar Motion Picture Group, Columbia Pictures, Sony Pictures Classics, Screen Gems, TriStar Pictures, Columbia Pictures Film Production Asia, Columbia Films Producciones Espanolas, Columbia Pictures Producciones Mexico), music (Columbia/Epic Label Group, American Recordings, Columbia Records, Epic Records, Roc Nation, Star Time International, RCA/JIVE Label Group, Arista Records, Battery Records Black Seal, J Records, Jive Records, LaFace Records, Polo Grounds, RCA Records, Verity Gospel Music Group, Volcano Entertainment, Provident Label Group, Beach Street Records, Essential Records, Flicker Records, Reunion Records, Sony Music Commercial Music Group, Legacy Recordings, MASTERWORKS, RCA Red Seal, RCA Victor, Sony Classical, Sony Music Latin, Day 1, Sony Music Latin, Sony Music Nashville, Arista Nashville, BNA Records, Columbia Nashville, RCA Nashville, Music Choice Video and Mustic Network, Sony/ATV Music Publishing).
Sony's Wikipedia page has a pretty comprehensive list of companies and technologies that they've created.
I'm not saying it's impossible, but you have to really think about what you buy. It's pretty easy for me not to buy a PS3 considering I'm an Xbox fanboy, but the movies and music gets a little harder.
With all that said, fuck Sony.
I consider a new device or technology to have been culturally accepted when it has been used to commit a murder. -- M. Gallaher