If you are not familiar with the concept of a tweetstorm, it is the term associated with bypassing the 140 char limit on Twitter.
So how are people doing this? By pre-writing you message, then chopping it up into less that 140 character message and tweeting them out in very quick succession.
It is a pain to execute, but works well for messages that have to be larger than 140 characters.
It seems Twitter have recognised this frustration and are actively testing their own built in tweetstorm feature.
Twitter user (Tweeter?) Matt Navarra reported the following:
This could be a very useful feature. Let us know if you have spotted this also