Portability is half the game when it comes to notebooks, and manufacturers have been pushing year after year to make notebooks smaller and lighter. Intel is getting ready to demo one of their newest designs, which promises to be the thinnest notebook in the world. The "Metro" notebook is very light at 2.25 pounds, and is thinner than many PDAs and cell phones. It is only 0.7" thick, though other dimensions aren't specified in the article. Regardless, that's impressive - especially if they don't have to skimp on other functionality of the machine.
The design is still in the prototype stage, so it may be some time before it sees life. The article speculates it may enter the manufacturing stage as early as this year, which would be doubly impressive. They'll definitely be giving Toshiba a run for their money with something that small.