Now that the world has moved on from making giant sharks float around by the magic of fancy air, we can move onto more interesting things like Portal personality cores.
Thinkgeek are selling two variants of the item you see above, Wheatley or Space, for $20 each. Sadly, they're not remote-controlled. They're basically glorified balloons. But they're glorified Portal balloons.
Portal 2 Inflatable Personality Core [Thinkgeek, via Copiously Geeky]