There are a few things you're not going to find in a netbook right now. None have an optical drive, and the highest RAM they support is 2GB. It's possible that Asus or Acer might have one with a DVD drive later this year, check the web.
Most have 120 or 160GB HDD's, except Lenovo or if you get one with SSD. Acer's are usually the cheapest but with the smallest KB's. HP's have 93% (92%?) KB's. The majority come pre-installed with XP Home, but you can install XP Pro or even Mac OS if you want. All will have webcams and mics. Go to your local Bestbuy to have a feel for the units first and then go online to find the best deals.