UPDATE, September 24, 2014: Apple has just pulled today's new iOS 8.0.1 update from its Developer Center and users are no longer able to download it as an over-the-air update.
Apple released the first iOS 8 update today - but hopefully you did not download it just yet.
The update, iOS 8.0.1, has apparently caused major problems for many users who report the update has interfered with their cell signal and created problems with Apple's Touch ID.
There are also a few reports that iOS 8.0.1 is also hampering iPad functionality, so if you did upload it, keep a close eye on your iPad's performance for the time being.
Don't panic early iOS 8.0.1 updaters - here's the fix:
If you updated immediately before hearing about the problems with iOS 8.0.1, here's what to do.
Connect your phone to iTunes and back up your data. Then, click the “Restore iPhone” button and follow the on-screen instructions. I know this is a terrible pain, especially mid-workday, but at least it’s better than having your iPhone turned into an overpriced iPod touch.
For those without access to a computer with iTunes right now, you’re unfortunately out of luck. I'll update this post if anyone finds a way to fix the issue without a computer handy.