Cleaning up the Pacific Garbage Patch
If there are a large number of freighters idled by the recession, they could be put to good use cleaning up the big Pacific Garbage patch.
I see two freighters trolling with a big net between them, picking up a current of garbage, and then maybe using it as fuel, rather than storing it (incinerating plant would have to be built in to the freighters).
This could be funded by the plastics council, and therefore, plastics manufacturers, since most of the garbage out there is plastic.