"Hymotion, a division of advanced battery maker A123Systems just emailed us to tell us that they're finally commercializing their plug-in Prius conversion module. The Hymotion L5 battery pack can be installed into any 2004-2008 Prius for just $10,000, giving it a fuel economy of more than 100 miles per gallon while the charge lasts (30 to 40 miles.) If you want to get a plug-in Prius straight from Toyota, you're going to have to wait at least three years...probably more."
Pretty cool stuff. I'm definitely in the camp that plug-ins are the wave of the future and though $10k is a bit steep for making this an economically powered decision, it's still great call for moving away from gasoline dependence.
I added it to the system so folks can add more info as it comes available or if someone tries it out. Product page is here or just click the image: