Before netbooks came into existence, portable pcs were categorized only into big clunky laptops and notebooks.
Asus practically created the netbook niche. I was one of the first amongst my peers to acquire an Asus EEE 701 -- the first that started the netbook craze. The Asus EEE 701 was small, portable and ultra cheap! Before this came out, ultra portable laptops cost 2 to 3x that of a normal notebooks. People at first didn't mind the dismal 7 inch screen, 4GB SSD HD, 900 mhz celeron, processor, linux OS, 512 RAM and the cramped keyboards. Everyone was amazed at the novelty of this ultra cheap device that you could tote around anywhere. It was the perfect gift, not only for tots, but also for adults. Stocks went flying off the shelves as everyone wanted a piece of this cheap ultraportable gadget.
Other manufacturers took notice and soon started producing their own line up with more beefed up specs. Amongst the notable early adapters are:

1.)
HP 2133 -- great build quality and heart stopping good looks with its magnesium alloy chassis, but it made a fatal mistake when it chose to adopt the VIA processor instead of the Intel Atom.
2.)MSI which came out with the
MSI Wind. It was one of the very first to feature a 10 inch screen, win xp OS, a wide usable keyboard bundled with a more powerful

intel atom processor and higher capacity laptop SATA HDs.

3.) Acer came out with a slimmer and cheaper
Acer Aspire One. 4.) Lenovo also joined in the fray and released the
Lenovo S10s -- sleeker,

and more expensive. I couldn't resist the metallik pink flavor (If you're viewing this page, you'd know my current obssession with pink) and happily ditched my Asus EEE for it.