The netbooks are fine for web browsing and certain other things, but not really sophisticated audio or video work. They are awesome to travel with - I have done it and now have a lightweight laptop on my wish list. The battery lasts a long time, the built-in camera is great for skype. OTOH, with the low processing power of the CPU and small screen, expect to run no more than one or two business applications at once. You should not pay more than $350 US for a 10-inch Atom machine. You can buy an external, USB-powered DVD drive for about $50. It is a bit of a hassle, but you don't need to carry it when not needed. I would suggest that you look for a dual-core Intel CPU laptops for any kind of real processing power. Don't go for the cheapest - it will last you longer. BTW, there are some thin and light notebooks (Dell Studio 14z, Lenovo U350, Acer Timeline) that may provide a good balance between portability (around 4 lbs), battery life, and screen size/processing power for around $600 (without built-in DVD).

Once again, the Windows and Macs machines have some advantages and disadvantages, and I would disregard the advice from anyone who only sees advantages of one and disadvantages of the other. Go for the objective advice, not PC-vs-MAC commercials.