Twitter has a popular iPhone app, but now some of its functionality is also built into Apple's latest mobile operating system, iOS 5. Tweeting a photo from the default camera app is now a tap away, as is tweeting a link from Mobile Safari. Tweeting is also built into the SDK, making it available via other applications without needing separate Twitter authentication.
You can see more photos from Engadget of the whole Worldwide Developers Conference keynote, where the above photo of the Twitter feature was taken.
Here's how Twitter describes the feature:
This means that you’ll be able to sign in to your Twitter account once and then tweet with a single tap from Twitter-enabled apps, including Apple’s apps—Camera, Photos, Safari, Contacts, YouTube, and Maps. And developers of all of your favorite apps can easily take advantage of the single sign-on capability, letting you tweet directly from their apps too.
The new feature perhaps makes the iPhone the biggest Twitter mashup since the new Twitter.com. And it's opening many new avenues for other Twitter mashups, as it's lowering the user experience barriers to create tweets from within iPhone apps.