If you have Windows Phone 8.1 and have been dying to try out the Project my Screen feature today is your lucky day.
The download is currently available on Microsoft’s servers here, and it seems to work pretty well.
Unfortunately the app is a Windows desktop app, not Windows Metro, but is still full screen on the desktop, making meaning you can not snap the app to the side of your screen or open it in a window and still get other work done.
To use the feature, install the Project My Phone app, activate Project My Phone in Settings, and connect your phone and run the app.
EDIT: Having issues having it up and running? This tweet from Matteo Pagani might help you 🙂