Go a few nights without enough sleep and you're more likely to get sick, but scientists have no real explanation for how sleep is related to the immune system. Now, researchers are finding that fruit flies can point to the answers.

Wal-Mart, the world's largest retailer, is starting to sag under its own weight, as it faces one of the most significant sales slowdowns in its history. The company has taken a number of steps to head off this inevitability, like selling more upscale products, but for the most part, nothing has really done the trick. Now the company plans to aggressively expand its sale of consumer electronics, including digital cameras and HDTVs. Some are wondering what the effect of this will be on competing electronics retailers, like Best Buy and Circuit City, with the latter already slumping on weak HDTV sales. The bigger impact, however, may be on the electronics companies themselves, since Wal-Mart is known to place extraordinary pricing demands on the companies that sell to it. As it is, there are already major concerns about a coming slowdown in consumer spending, so between that and Wal-Mart's monopsonistic practices, a number of electronics makers could be feeling some pain. Also, as part of the new push, Wal-Mart plans to start selling Skype-branded internet calling gear. It will be interesting to see if the company can sell low-cost VoIP products to a customer base that's always looking for a bargain.

A professor has developed an unconventional alarm clock every new parent needs -- a clock to keep their children sleeping. Called the Reverse Alarm Clock, the product aims to keep young children from interrupting their parents' sleep.