THE WALL AND THE WING, by Laura Ruby (HarperCollins, 2005) is a wonderfully and ironically zany new novel by the author of LILY'S GHOSTS.
In an alternate New York City, Gurl is the only one who can't fly. What she can do, though, is become invisible, a talent which allows her to escape nightly from the Hope House for the Homeless...until she's caught by the House matron, who blackmails Gurl into stealing for her so she can maintain her extravagant lifestyle (that includes expensive plastic surgery, caviar, and other luxuries). There are a lot of twists and turns, and a lot of quirky characters, including fellow orphan Bug, gangster Sweetcheeks Grabowski, creepy mechanical monkeys, a cat who makes effective use of indoor plumbing, and a mysterious Professor. It's enormously fun getting to the bottom of who's doing what to whom and why.