Well, as far as I know, much of the stuff for linux doesn't contain spyware. Adware maybe...but not too often. Opera 7 is the only thing I can think of that would have adware on linux. But if you want to avoid popups and whatnot, try mozilla. It's pretty good about blocking that kind of stuff. But if you're feeling a little paranoid, you could go through all of the services that run on your computer, and block off ones you know you don't need, or set up a firewall.