Twitter creates more 'Cards' for displaying multimedia content, keeping with its 'build into Twitter' strategy

Twitter held an invite-only, closed-to-press developer event tonight, and the agenda was helping those developers build features that can appear on Twitter's website and in its own apps. The new cards that Twitter is offering will allow developers to display photo galleries, media players, "deep-link" to apps, and more within a single tweet. The news comes from Dave McClure who, appropriately enough, is tweeting details about the new cards. Flickr, Path, and Foursquare have all taken to the stag...