This may not be what you want exactly, but I recently added an option to powerCall https://play.google.com/store/apps/details?id=com.mk.fastcall
to unlock the device with power button double-click. It bypasses swipe lock screen. I am currently looking into an issue with this app on GS3 (stopped working after Jelly Bean upgrade, but works on many other devices in JB and others). Let me know if it does the trick on your device.