What is a good air purifier for a cubicle?

My fiance works for a large airplane manufacturing company and is often miserable because of his cube conditions. He is looking for some kind of fan or ionizer that is very small (like desk size), quiet, and preferably runs off of the computer’s power. He isn’t allowed to take in anything the size of a regular fan (like a tower fan) and would need something super small. I saw the Day-Timer Ionic Air Flow Fan with Clock on Amazon.com, but after searching the internet, I couldn’t find any actual reviews of the product. Has anyone used anything that they would recommend?