A lot of twitter users will tell you the 140 character limit imposed by the official twitter applications and web takes some fun out of the twitterverse, that is why alternative twitter clients like Ubersocial, tweetbot & echophone were made to allow you shorten and send tweets longer than 140 characters automatically and send without hassle.
With recent twitter client updates, the Twitlonger Mod which provided an easy solution to the 140 limit on native twitter app does not work anymore.
The TweetDeck application which is a Good alternative to help tweet more than 140 characters and shortened with deck.ly has been acquired by Twitter and part of the first changes they made was to restrict tweetdeck to 140 characters (Both Browser and Phone versions).
There are other Apps that can tweet more than 140 characters but twitter seems to be gunning for the most popular ones.. I guess UberSocial is Next on their list...
Solution to tweet more than 140 characters on native Twitter App The alternative to twitlonger which also uses pastie.org to shorten tweets automatically is called
140plus.
140plus for Twitter Mod made by moeseth is available for download on Cydia Bigboss Repo.
Install ==> Respring your device and Reopen Twitter app
The New Twitter + 140plus Mod installed