Help identifying this tree/bush/plant

[gshank]

I have no idea if this is a tree, bush, or something else but I found a sapling growing under my back porch steps and I dug it up and replanted it where it has been growing very fast but I can't tell what it is. I used the "tree finder" thing on the arbor day site and other google searches but I'm still not sure what it is. I uploaded 2 pictures to the imageshack site: http://imageshack.us/g/840/tree1d.jpg/ - hopefully these are enough to tell.
Thank you for your help.
Gary

[fusion2]

Datura is any of several members of the plant genus Datura, including D. wrightii and D. stramonium, commonly known as Jimson weed, thornapple or loco weed

[gshank]

Thank you. I think I'm going to dig it up and get rid of it.