Yesterday, Apple was granted yet another patent for slide-to-unlock, and it's even more general than the first two.
The new patent throws a lot of the limitations of the others out the window, specifically the part that required an unlock gesture to move along a very specific path. Now there are just two main guidelines to keep in mind. One is "continuously moving the unlock image on the touch-sensitive display in accordance with the movement of the detected contact," which is to say moving your finger across a touch screen with no real route.
The other is "movement of the unlock image from the first location to an unlock region." So there's no indication that you have to start or stop in an exact location. And all of that leaves Apple's rights for slide-to-unlock very vague, but at the same time very broad and very open to interpretation, which is probably just the way Cupertino likes it. [The Verge]