Is there an HDMI to 3.5mm stereo converter?

I just installed a new video card (Sapphire HD 5870 1GB PCI-E) and in addition to the DVI-I output it also has HDMI. I’m currently using the DVI output to my monitor and have an old Audigy sound card. In addition to using the DVI for video, can I use the HDMI output for the sound only? What I mean is will it give me better sound quality than the Audigy sound card? If so, how can I attach it to my amplifier? I’m using Windows7 btw and the drivers for the Audigy sound card still are not the best.