That's what netbooks are about; small, cheap laptops. As a result they do away with stuff like optical drives.
Over time netbooks have become larger while laptops became smaller/lighter, so there's not that much difference anymore anyway.
It should be possible to use a netbook on your home wireless or wired network, though if you want to use it on the road, you probably want to have a "mobile" ISP. Think you just get a USB device with an antenna in that case.
Can't speak from experience though; I keep away from both wireless networks and anything smaller than a desktop PC.
