There doesn't seem to be much of solid chance of achieving this. I found this method on Lifehacker, and I haven't tested it, so try it at your own risk.
The first step is (again, always) to back up your device. Next go get the build of iOS 6 that your phone runs. If you've got an iPhone 5, that means grabbing iOS 6.1.4, the CDMA flavor if you are on Verizon or Sprint, and the GSM flavor if you are on AT&T or T-Mobile. If you've got something else (iPhone 4S and below, iPads 2-4, iPod Touch 4 or 5, or iPad Mini) you'll want 6.1.3. The same CDMA/GSM logic applies.
Did you back up your device yet? Back up your device.
Now put your phone into Device Firmware Update (DFU) mode by plugging it into the computer and holding the home button and the power button for 10 seconds. Then let go of the power button and only the power button, and keep the home button pressed down for another 10 seconds or so. The screen will stay black, but iTunes will detect a phone in recovery mode. It's worth noting that this isn't strictly necessary, but it does make matters a little simpler.
Ignore any restore prompt iTunes throws at you. Specifically this one.
Open the panel for your iPhone and option-click/shift-click (OSX/Windows) on Restore iPhone.
This will give you a dialog box popup; use it to go find that ipsw file you downloaded after you backed up your device. And bam, you should be good to go. If things aren't working, try booting up your phone, disabling Find My iPhone, and do it all again.
There you go, back to skeumorphic goodness. Now just avoid installing iOS 7 for as long as you can bear it. And while you're doing that, try to make peace with the fact that iOS 7 is coming for you eventually, and there's pretty much nothing you can do to stop it.