Frys has this Thule backpack for $37 with no coupon code. I think the green one was a little less before. This is for one is black, 25 liter. Says it fits up to 15" Macbook pro.
Large main compartment keeps daily gear separate from the electronics
Hideaway lash points with reflective detail
Organization panel keeps small items secure and easy to locate
Quick-access pocket on front panel
Airflow channels on back panel provide ventilation