It’s a shame that the majority of new smartphones lack a dedicated camera key. It’s awkward to use the on-screen shutter control, especially in situations where steadying the camera is required to take a clear photo (like when taking a macro shot). With a bit of software tweaking, developers have come up with ways to assign the shutter function to existing hardware buttons. In some cases, the volume up/down rocker is used. As in the case of this mod for the AT&T Samsung Infuse 4G, the power button is utilized to take on this function. Over at XDA, user Frooty has posted an easy-to-install APK that not only allows you to use the power button to capture photos, but it allows you to take photos and video even when the battery is below the critical 15% point.

Source: XDA