Could be an advertisement banner
RD,
I won't speculate if it was or was not an UFO. I do believe in UFO, since I saw one about 30 years ago, and it was no gov't experiment plane, since we still do not have the technology to make a plane completely noiseless flying about 1000 feet overhead. However, from the pic, it looks like an advertisment banner that has been flying around the SW burbs. I actually saw it on Sunday over the Fox Valley Mall area, and it was a huge banner and shaped exactly like the shape shown in your photo. Watch for it, because the last couple of weeks, I have kept seeing alot of aerial advertisment going on around the SW burbs.