Laptop Recommendation under $1k

Looking for a laptop for my girlfriend, either PC or Mac. She's coming from a dog-slow old Dell Inspiron 15" tank from several years ago. Here are the requirements:

Quick: Fast enough for internet, Word, iTunes, etc. No gaming, photo/video editing, etc. Just basic stuff.

Small: 13" is about the right size. 14" would be okay. Thin is good.

Light: As light as possible as it will be used for bringing to work, school, etc in a backpack.

Inexpensive: As inexpensive as possible. $1k is the absolute MAX, but she'd prefer closer to $700.

Thoughts?

 

I also made a post on the Mac forum with a more Mac specific question: http://www.theverge.com/2011/11/6/2543321/need-a-mac-recommendation