If you're paranoid about cracking bwgen or want to use Linux, (or both!) use sbagen - http://uazu.net/sbagen/ - it's for Windows and Linux. The downside is that it's a little confusing to use other than for the example binaural beats it comes with (although there are a lot of neat ones) . To play the examples just install, open up the example folder, and double-click whatever one you want to hear. (Not sure if that's the way it works on Linux, I've only used it on Win XP so far). If you look around on their site you'll find a link to their wiki and if you look around on that you'll find a version of the program with a GUI (Graphical User Interface). I haven't used the GUI much yet; I've just been listening to the examples. Some examples are from the Monroe Institute CDs. Check it out.