My niece called me the other day asking why a video she uploaded to YouTube from her mobile phone displayed sideways. She wanted to know if there was a way to rotate it so it displayed correctly.
For those who may not know this, YouTube does have a Video Editor that they launched back in June. It's a nifty little editor for those who don't have (or cannot figure out) their own video editing software. It allows you to rotate, trim the beginning and ends, and add music to your uploaded videos. If you have a few videos you want to combine together, you can also add transitions between them. (Caution on the music/audio swap feature because if you add music, it will delete any previous audio associated with your video). Once you have edited your video, you SAVE it, give it a new TITLE and PUBLISH it.
So, for those of you who have experienced the same situation as my niece, here's a short little tutorial on how to correct it within the YouTube Video Editor.