Looks like Panasonic is ready to take on Sony's Librie. While the Sony ebook reader hasn't been a huge commercial success, it's won plaudits for its sharp, highly readable grayscale display. Now, Panasonic, which previously produced the less-than-stellar, grayscale, dual-screen Sigma Book, is showing off a prototype that offers full-color and a resolution of 210 ppi on its 5.6-inch screen. The company also says the reader will incorporate Li-ion batteries with a six-hour lifespan, and a USB port for uploading ebooks. No idea yet if it'll use proprietary software like the Librie (it probably will) or if it'll ever be available outside of Japan (it probably won't), but we'd still like to get a look at that screen. The reader is expected to be available in Japan in about a year, for about $360.