After Apple’s purchase of face recognition software provider Polar Rose, we were unsure what Apple had planned. Now, thanks to a little 9to5mac digging we know that face recognition (FaceRec? FaceTimeRec? FaceSnatch?) will be baked deeply into iOS 5 and support a number of clever features including, potentially, the same wacky effects available in Lion’s Photo Booth app.

Photo Booth, for example, uses Polar Rose’s technology to add tweeting birds flying around your head and to specifically change your eyes or nose rather than your entire face. This feature has been available with some webcams for a few years on Windows and is only now trickling over to the buttoned-up Mac world.

The API supports a call to mouthPosition as well as left and right eye positions. There are no clear examples of these API calls in the OS itself but developers could, for example, use them to make better, more accurate fart apps and to take Talking Tom to dizzying new heights.