Cortana now works on Windows Phone even when your phone is locked; that is if you're running the latest version. Windows Phone 8.1 Update 1 is full of surprises. Live Folders are an obvious feature in the update, but a lot of other things, like custom snooze times in the alarm app, are still being discovered. Being able to use Cortana while the phone is locked is another one of those small features we're just discovering.
Using Cortana when the phone was locked before Update 1 only gave you access to controlling your music and the ability to initiate calls. Now, after Update 1, you're able to use Cortana to ask questions and get results.
Worried this might allow someone to snoop around your phone when it's locked? Swiping over to the Phone pivot won't show you the results you'd see if your Windows Phone was unlocked.
Just another little feature making Cortana (and Windows Phone 8.1 Update 1) very useful. Finding any other cool tricks inside Windows Phone 8.1? Check out the Windows Phone 8.1 Update 1 forums to share them!
Thanks for the tip thaman04