Turtle Beach - Audio Advantage Micro USB Audio Adapter - TBS-1120
My Dell computer has the crappiest headphones jack. Every time I move my mouse around, it sends static through the headphones. Insert this puppy into a USB port, select it as your audio output device, and set the volume LOW, because it has some serious gain. You'll be listening to glitch-free audio in no time. Plugged right in to my ubuntu linux system and worked without a hitch. This is much cheaper than the HeadRoom Total BitHead Headphone Amp and it did everything I needed.