I bought one of these two years ago and it's the best carrier I've ever had and I've had a lot. It's not especially pretty but when you're going on trips and need to sneak the little ones into a store or other places when it's too hot or cold to leave them in the car, it's perfect. No one ever knows he's in there and it's completely machine washable.
Two years old and looks brand new still. Mine little one is a bit of Houdini and can squeeze thru openings on the bags that have zipper closures. But this one is a drawstring closure and has 3 mesh sides. Also has 3 pockets. Pockets on the sides are big enough for my wallet and/or his water bottle.
I highly recommend it. here is the link.
http://www.uniaccs.com/categories.asp?id=3
It's the In-Dog-Neeto (like incognito!) bag.