Cleaning oil spills with a net!:

http://phys.org/news/2015-04-scientists-mesh-captures-oilbut.html

This can be a real breakthrough for cleaning up our fuel messes on the ocean.

Nice idea, but major oil spills cover such vast areas that it would probably be impractical to drag a net around. Of course the thing would also fill up with plastic in no time. (good for the oceans, not so good for getting oil).