* Make the popup permanent by pressing the SPACE BAR
* Press 'L' to watch videos in cinema mode
* You can drag around the popup and also re-size it
Move your mouse over YouTube links on any webpage and YouPop will open the video in a popup. This way you can preview videos easily. Move your mouse away and the popup will close. In case you decide to watch the rest of the video, hit SPACE BAR to make the popup permanent. You can then drag it around and re-size it to your liking. Press 'L' to toggle the 'lights out' effect.
Here's a demo. Thanks TruthJunkie2012 for the demo video! :)