Mary Lou Jepsen—the XO Laptop's designer and OLPC's CTO before defecting and founding Pixel Qi—has even grander ambitions for new laptop project than hitting a mythical $75 pricetag. Pixel Qi is working on a laptop will be able to run on a standard for 20 to 40 hours, no pixie dust required.
How? It's all about the screen. Just just like she reinvented the LCD screen for the XO, making the project possible both costwise and practically (with the flip of a switch, the color LCD can switch to one that's monochrome and highly reflective, making it easy to use outside and even more energy efficient) she's trying to do it again with Pixel Qi's latest. Their incredible efficiency is what will allow the laptops to possibly run for 20-40 hours.
Obviously, she wouldn't spell out in detail what's so magical about their screens yet. In an email to PC World, Jepsen simply says that:
"At Pixel Qi, we have a new series of inventions that go well beyond the OLPC screen that we are developing right now... We can enable an increase of 5-10X battery life between charges compared with a standard notebook. This means that rather than needing to recharge your batteries every few hours, you could run 20-40 hours of use on a one charge."