Akin to the skylight, but less prone to leaks, and much less expensive, more flexible, and easier to install. Downside: Unlike the skylight, there is no "view" outside. Ours is sited in our kitchen and reduces the need for artificial lighting during the daytime by 50- 100% (depending on the weather and what I'm doing). These have been around for awhile, so the technology is not new.
It was extremely handy to have during the Great Power Outage of '07. It cost about $500 to install, (although you can buy and install them yourself) and will probably never "pay" me back completely, (unless the grid really does go down) but I would do it all over again! At the time, I could barely justify the expense. But I really do like to have daylight.