Youtube links in org-mode, see https://emacs.stackexchange.com/questions/38098/org-mode-custom-youtube-link-syntax
After installing and loading this library in emacs you can use links with the format
[[yt:<video-id>]]
or
[[yt:<video-id>][description]]
in your org-mode document. If you display inline-images in org-mode the link is replaced by the image for the video downloaded from youtube. When you click on the link or on the image the video-url is opened in the browser.