I haven't used it,but I think Jared Sinclair's Stormcrow app is intended to build a tweetstorm from z bigger chunk of text, so it would be reasonably easy to use either before or after writing the blog post, if that's what you're doing. There's clearly a difference between text and tweetstorm, though, and, like @nitin, i would prefer to promote something I had written with selected tweets.