What is it?

MARCH 9 UPDATE BELOW!


I found this gem in the most unlikely place. Can you guess where?




This graceful little nest hangs just above the ground beside a path in the local woods.





(click for larger image)
It was perhaps a foot off the ground and was pendulous like an oriole nest. It was approximately 5 inches long and at the widest part, maybe 3 inches. Any ideas as to who built it?


March 9 UPDATE:
NEAT! Tom from Ask a Naturalist.com has solved the mystery! He consulted two experts and the consensus is red-winged black bird. An oriole nest is also a possibility. Thank you Tom!

EARLIER UPDATE:
My friend, Jonna, suggested perhaps, that the nest belongs to a Red-eyed Vireo! This from a site called Familiar Birds of America:
"Nesting.--The red-eyed vireo builds a dainty little pensile nest suspended usually from a forking, horizontal branch of a shrub, or low branch of a tree, rather below the level of our eyes as we walk through second-growth. The nest is a beautifully finished piece of workmanship, constructed of fine grasses and rootlets, bits of birch bark, and paper from wasps' nests, bound together and to the supporting branches with spider's or caterpillar's webbing, and, perhaps the most constant material, long, narrow, flexible strands of grapevine bark, which help to hold up the cup of the nest. It may be ornamented on the outside with bits of lichen. Dr. Arthur A. Allen (1932) says that it has thinner walls usually than other vireo's nests."