Six Moon Designs Starlite Backpack - 67L (weight including stay is about 28 ounces)
Includes standard shoulder straps, size medium hip belt with pockets, and optional stay.

I purchased this pack new in November 2013 and used it on several 2-3 day trips this year. It performs very well as an ultra light pack and handles up to about 35 pounds reasonably comfortably. Definitely a quality pack and good design.

Features:
Waterproof material (I used it in the rain and everything inside kept dry)
Very large mesh pockets on the outside (see pictures - they hold a LOT)
Roll top with velcro closure - helps minimize volume as needed
Hip belt pockets
Internal zippered security pocket for stuff like keys and wallet
Stay is removable
Adjustable torso
Zippered storage against your back for a sit pad (which adds rigidity and cushion)
Whistle
Attachments for a hiking pole

Please see the photos.

I'm asking $129 shipped (CONUS). Payment via paypal.

Photos Link: https://plus.google.com/photos/113447840227515281513/albums/6076974769813769697?authkey=CJGu2Yf-_tSqQQ
(Note - the bottom of the back expands more than shown in the pictures - I stuffed it with a few pillows.)