netbook would be great if all you wanted to do was word process, use internet, watch some vids. they easily come in your price range and are small and light, but don't expect to be doing any gaming on them.
good brands: asus (eeepc is excellent), and i think there's a dell one but idk how good that is, there's a samsung one, but i'd stick with the eeepc since my sis has one and she gets 6hrs battery minimum, and you can get up to 8 (apparently 10hrs) if you apply all powersaving techniques (brightness down, wifi and bt off, sound off).
laptops would be good for a lil bit of gaming and the rest of the above, but are a bit more pricier and larger and heavier than netbooks.
good brands: asus, toshiba, dell.
if you're not interested in gaming at all, or already have a desktop/console at home, then your best bet would be to go with netbook for its mobility and price.