The most popular video API is about to become more popular. As just announced by Googe's Jim Patterson on the YouTube blog, YouTube Everywhere, the YouTube API has just been upgraded with some very powerful new features.
No need to send your users off to get embed code, the snippet of text needed to include videos and other rich media in a web page. All you need is the original URL to the content and Embed.ly returns the HTML you need, along with plenty of other useful meta-data. And it supports an impressive list of over 100 sites.