Great idea, but think not very practical for the heavies, especially in weather or night.
Our "lights" did it on the wing of a tanker crossing the pond. Don't get too close to the heavy's centerline, however, or you'll roll into him.
So one day I fell behind a bit on purpose and maintained nose-tail clearance, then moved in. Wow! took lotta aileron and such, but I could feel the "surfing" aspect easily. My fuel flow went down about 25%.
And just look at the migrating geese and cranes!