Mark McDonaldwrote a review of Arc'teryx C80 Chalk Bag on February 18, 2010
I had another bag that I didn't really think much about, it wound up being too narrow. I couldn't get my hands in it even without it belted. The c80's awesome, it's not that long (it does look sort of long in the pictures) but it's very wide-mouthed and between that and the stiff brim, it's awesome. The pocket's great and doesn't bleed chalk or anything through to your cell-phone or wallet (yet it'll fit a wallet) the angled brim makes dipping incredibly easy and the one I got in black looks amazing.
It may be a few bucks more than other chalk bags, but compared to fussing trying to get your hands in one in the middle of a circuit at the gym or where-ever else, you're better off spending the extra 6-$10 and getting the bag you'll be happy with.