I love these! How rad, add a mini garden to practically anywhere... I came across them on the Ruffled site, where they've got a tutorial on how to make your own. They were made as wedding favours, which is an awesome original idea, but there's so much you can do with this to adapt it to suit any area you want. Something about looking at them just makes me feel so... zen.
I think I'd like one in my car.
check out the how-to here.