A start-up company in California, Practical Instruments, has produced a prototype of a solar concentrating panel called the Heliotube. It consists of 10 small solar troughs that rotate to follow the sun. The troughs are integrated into a panel that is the same length and width as a traditional panel (60" x 42" x 6") and weighs 45 pounds. Company CEO Brad Hines says the design is meant to fit into the existing solar panel industry's delivery network for commercial buildings and potentially for residential homes. You can see a close-up view of the panels after the link.