And just to add my two bits - for an inverter you're looking at a 10 to 20% power loss, depending on the model. So that'll decrease you're on time by a not insignificant amount.

The "pop-up video" bubbles that appear when you play music have to be one of the coolest uses of Ajax I've seen on the web so far. I keep clicking around the site just to see all the great Ajaxy design elements.