Super simple cheap solution -- disconnect/remove the existing fan & hook up a bigger quieter fan to blow on the cooler. Use zap straps, insulated wire, whatever. The card is said to consume just 19 watts of power under load -- this should be a cinch to cool. Especially if HD video play is the most demanding task. If you're handy, an old aluminum CPU heatsink from P2/3 days could easily be repurposed as a silent/fanless cooler for this card. The GPU should have a thermal sensor you can use to monitor temperatures via the ATI/AMD Catalyst control center or whatever temp motoring software of your choice.
Thanks. I'll give that a whirl and post the results and pics once I'm done.