No, that 150 x 150 image was a sample created by a member who was showing us some of their ideas for banners. We ended up creating two sizes: 500 x 63 and 125 x 50. And you can get to those by browsing to your vehicle profile (under "Your Garage" on the left) and clicking "Get your own Fuelly badge" in the lower left.
I've seen that smaller badge on a few blogs. And the larger one seems more popular for forum signatures.