Apple pushed out iOS 6.1.1, which Vodafone says is A-OK by the way, but it did nothing for the battery woes of legions of iPhone users. Microsoft to the rescue? It's pushed out an official support document that aims to try and fix it, until Apple actually gets round to crushing the bug.
So, what does Microsoft suggest? Well, it seems the battery is guzzling is caused by a glitch in iOS 6.1, which results in a continuous loop connecting to an Exchange server, draining both the device's battery and the resources of the server.
The fix? Don't process calendar items like meeting requests on your phone. Also, you should immediately restart your iOS 6.1 device if you do happen to click accept on something. Microsoft also recommends deleting and re-configuring your email account on your iPhone, which sounds sensible to me.
For a full list of work arounds, you can grab Microsoft's support document here. But, basically, it seems like you're just going to have to proactively avoid Exchange and reboot your device regularly if you have to use Exchange for work or something, until Apple outs a permanent fix for the glitch. [Microsoft via 9to5Mac]