Day Pack for Fast Day Hiking/Running

I have an Inov-8 running waist pack for sale on Gear Swap:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=75089&skip_to_post=642021

Edited out. Missed the part about running.

I just ordered a Platypus Origin 9 from REI. It is a running pack that comes with a Platypus 3L Big Zip. It is also waterproof. It is on the heavy side at a bit over 1 pound without the reservoir, but is in the range for what I have seen for running packs. I haven't received it yet, so can't comment on how good (or bad) it is.

I got it for 40 with my 20% off. They also have 3l, 5l, and some in the ~20l area.

Here are a few to consider;
Golite rush series
Ultraspire fastpack or other models
Terra nova laser 20

You can grab a camelbak waist pack with two podium chill bottles from Bigskycountry.com for a ridiculous price. The chill bottles alone are usually $12 each and the pack, with 2x bottles, is only $20. Free shipping over $45.

Site may be going out of business though so it's a gamble, cheap, but a gamble on customer service (I ordered from them recently and through bad shopping cart etiquette on my part they were out of stock on a lot of my purchases and called me to fix the issues, so it's still great customer service for now).

http://www.bigskycountry.com/camelbak-delaney-dc-2-podium-bottle-hip-pack

For a pack designed for running that wont bounce I have to recommend the Salomon Skin series of packs.

The skin 5 is excellent for water, water treatment, some snacks, a shell and some other essentials like a headlamp, first aid, a camera and compass etc.

The Skin 12 will comfortably carry just about anything you could think about carrying for a long day. There are people on here who could fit their overnight gear in it. I like it over the 5 when I want an insulation piece and maybe some larger food items.

There are other sizes as well, but I have no first hand experience to contribute.

Don't play the gram counting game when it comes to a pack for running. Get one designed for the task as comfort will come more so from weight distribution and reduced bounce than weight on your shoulders.

Thanks for all the input everyone! This is great. I just ordered a lumbar pack from a fellow BPLer but will probably be getting one of the above mentioned packs as well. Psyched!