In another step towards filling all its holes, Twitter has just announced its own link shortening service which starts rolling out today. The Twitter link shortening service will pass through t.co and shorten links to 19 characters, still allowing users to see what site the links are pointing towards (see above).
From Twitter support, on how to use the new shortener.
Start typing or paste a long URL into the Tweet box.After you’ve entered the first 13 characters of a URL, a message will appear at the bottom of the Tweet box, letting you know that the link will appear shortened. (Fig. 1)Notice that even if you’ve reached the character limit, you can continue to add text to the URL with no consequence.Once the Tweet is posted, it will be assigned a t.co link ID, but the link will appear as a shortened version of the original URL, so people who see your Tweet will know the site they are going to (Fig. 2, above).Yep! It’s now that easy.
In an afterthought, Twitter users are still referred to third party apps like Bit.ly if they want analytics surrounding their links. [Insert well-trodden assertion that Twitter is breaking the hearts of its developer ecosystem here.]