Most DAW software has pitch shifting plug ins incorporated in their software: Sound Forge, Sonar, Audition, even the editing software applet that comes along with Sound Blaster Audigy, but don't expect miracles, none of them are perfect. They will all add a little flange to the finished sound. The thing you have to watch using it is to make sure that you don't go so far trying to transpose a song to a different key, that you get instruments playing where they can't actually play. I hate it when I hear a guitar playing notes that are not possible because they are lower than "E" below middle "C".
