I'm having fun writing code for real-time audio effects.
If you have Chrome or Firefox, you can play with this Waveform UI toy. Click the play button to start the audio, click and drag on the dots to change the sounds!
You can experiment with what different wave shapes sound like. In general, smoother curves have less high-pitched buzzing, because there are fewer harmonics needed to approximate that curve. I haven't found very many interesting sounds in the time domain like this, though, so you'll have to wait for further experiments to make a variety of textures.
The "cut" setting, if turned on, takes a part of the waveform and sets it to 0. (This isn't reflected in the waveform graphic.)
I made the interface using raphaeljs, which I recommend. This project is made possible by Firefox 4's cool raw audio data api. Thanks to those at Mozilla.
