Too many netbooks are severely under-powered. I have seen a number of them in a lecture where they took at least a minute or two to boot up, and that is before Windows actually starts up, so it's mostly a hardware issue at that point. Just get a regular laptop instead, there are very affordable ones with decent built quality. Macbook, an obvious good choice because of the strong OS and hardware, but pricey. Windows 7 based laptops, also excellent, more affordable and Windows 7 is an almost flawless operating system.
Either will be a good choice, I am going to give a nod to the macbook, simply because it's a worry-free out of the box experience.
As for the the ipad, it's not a great laptop replacement.