Apparently someone posting on Abovetopsecret did:
This sounds pretty much like what I've seen, the only difference being that I could tell it was MUCH larger than a basketball... it went behind the tree line and was close to half the width of the 80-foot-tall or so pine trees in our neighborhood. I live on the very western edge of town, and there's a creek there, then a highway, then... nothing really. it looked like it was going from southeast to northwest.
Here's a picture of what I saw:
Just a big, blue ball of bright light determined to get somewhere fast.
Ball lightning? Or what else do you think it could have been? People on the abovetopsecret thread I linked associate it with a bright flash of light...