If your computer room is full of dust and smells (which I guess depends on who you site next to) then there is a USB (well what else) solution. The catchy named IAP565A Car & Computer Air Purifier.

Simply plug it into a vacant USB port for the following results:

• Circulates millions of negative ions inside of your Car or open area in the home or office
• Remove many types of particles & pollutant, including airborne dust , harmful allergic such as pollen, pet dander & smoke particles efficiently
• Eliminate the cigarette smoke thoroughly
• Collect microscopic contamnants in the air
• Destroy micro-organisms such as germs,viruses,bacteria
• Helps to reduce odors

Available from Inovixproducts.