Air purifiers come in all shapes and sizes. So far, though, I haven't really seen anything similar to the Andrea, which cleverly combines modern air purifying methods with nature's own.
Instead of employing slabs of filter, UV light or ionization processes to do its cleaning, the contraption uses good ol' houseplants to remove impurities from the air. Of course, you'll need to use plants with specific pollution-purging properties to have it accomplish proper purifying. The website suggests a few, including aloe vera, dragon tree and spider plant, among others.
The Andrea Air Purifier consists of a special container where you can grow an actual plant, with soil and fertilizers and regular watering and all that. According to the website, the plants' natural metabolic properties will sift through the air in the room, eliminating unsavory elements before spitting it back out, clean and fresh, using onboard fans.
Without scientific numbers comparing it to those awesome plug-in air purifiers, though, it's really hard to tell how well this thing works. However, it did win a design award for its creators, French designer Mathieu Lehanneur and Harvard professor David Edwards, so it might actually be really functional.
Artsy French online store, Labo Shop, has the Andrea Air Purifier on sale for €149 (around $200). And that's just for the case -- you'll need to supply your own plants.