Crate Fans

We are in need of another smaller fan that can be used for traveling and when the dogs are in crates. I'd prefer it be cordless, but it'd be ideal if it could plug in and use a battery.

What is everyone using for crate fans? Are the Ryobi still the prefered ones that most are using?

I love the O2 fans. They run on batteries my big one takes 8 "D"s), and can also be plugged into an outlet or cigarette lighter in the vehicle. And they're quiet. I think my big one is 8 inches. It might be 10, tho. My smaller one really is better for sitting by the computer than for Caleb.

http://www.o2-cool.com/battery-operated-fans