The RoboSwift, built by researchers at the Delft University of Technology, is among the first flying machines with a "morphing" wing sweep. As you'll see in the video below, its wings reduce in surface area when pulled back to limit drag, the way the wings of actual fast-flying swifts do. Unlike the real birds, however, the RoboSwift is designed to spy on you.
Inside its small body (20" wingspan), there's a low-resolution wireless camera. The idea, already thought to be a good one by Dutch police, is that RoboSwift can be used to surreptitiously hover over crime scenes or football riots. People below, if they did look up, would only to see a soaring, swooping bird of no consequence.
The dudes from Delft are so proud of their little 85 gram beast, they reckon they can even use it to observe other birds without being noticed—they just have to find a way to fold up that propeller once RoboSwift is aloft. Stashing that long-ass antenna on the end of the tail might help too.