Facetime
Why have I lost the use of the isight camera?
MacBook Pro (17-inch Early 2011), Mac OS X (10.6.8)
chellmitch wrote: Why have I lost the use of the isight camera?
Because something is wrong.
If restarting your Mac doesn't get your camera working with any camera-capable app (example, Photo Booth), one of the suggestions in http://support.apple.com/kb/HT2090 will correct it.
(Over time, Apple has changed the built-in camera's name on newer Macs from "iSight" to "FaceTime" and then to "FaceTime HD." Regardless of the name of your Mac's built-in camera, the same info and troubleshooting applies.)
If your trouble is ONLY with the FaceTime app, take a look at http://support.apple.com/kb/TS4185