Price range is pretty important information.
How about something with an E-350 APU, like the HP dm1z? That has an 11.6" screen and is often available on sale at under $400, and weighs around 3.5 pounds or so and can go a good part of the day on battery. Battery life may be important because then you can ditch the power brick at home. Look up some reviews.
Otherwise, let us know what screen size you are looking for. Basically for light weight, 13.3" and smaller with no optical drive are the usual culprits.
Are you afraid of refurbished or recertified items?
If you want battery life and are concerned about keyboard/screen being too small, how about a Dell Vostro V131? It uses a 13.3" screen and normal notebook keyboard, plus has 9 hours battery life. Unfortunately it starts at $500, but CPU performance would be better than the dm1z.
Welp, my price point would be under $400. I was looking at the dm1z on HP and with a student discount for the base model it comes to $380. It seems to fit the bill, but I'm wondering if have a 11.6" screen will be a bit annoying to use. Not necissarily because the screen is small, but the keyboard. Has anyone used this and have feedback on that? I have no familiarity with small laptops.
And battery life definitely matters. I don't plan on taking the power cord around with me. Just maybe a mouse and headphones.
Also, the DMZ 1 seems to have been released a while ago. Should I worry about something newer just around the corner or currently on the market?