Ye' old general discussion board. Basically, for everything that isn't covered elsewhere. Come here to shoot the breeze, shoot your mouth off, or whatever suits your fancy. This forum is not for asking programming related questions.
There's a few ways. The common one is to wrap it in a Flash loader and stream it to the browser. That way it won't show up in the cache. Another way is to base64 encode it, embed it into a JS variable, and load it into a canvas using DHTML ... very nifty. Neither method will stop people screengrabbing it though so it's a bit pointless if you're trying to protect it.