oEmbed has been around for a while and there are some really nice implementations of it. For example, in WordPress, where pasting a URL to YouTube video, Flickr photo, Twitter tweet, and a number of other services, will result in a nicely formatted embedded snippet from an external site. WordPress does not only consume the oEmbed, but also provides embeddable content.
For a while now, I’ve been thinking about ways to utilize it. There are quite a few applications of oEmbed that make sense for our projects at work. For now, I’ll just leave you here with the link to the oEmbed specification.