Twitter limits users to 140 characters, but sometimes that just isn’t enough. Some Twitter applications have started to take advantage of third-party services that let users post longer messages, and then in the tweet it will provide a link to the text. In many ways this defeats the purpose of Twitter, but sometimes you just can’t fit what you want to say in a mere 140 characters.
Posterous is probably one of the more widely used services for this purpose, and it also lets you include things like images, videos, MP3′s and more. It has pretty much turned into a personal blog for a lot of Twitter users, but a.longreply.com looks to bring the simplicity back to your long tweets.
The homepage pretty much consists of a text box and a submit button. Once you submit your message it will provide you with a link you can use for your tweet that is over 140 characters. When people click through to read the message they will get a fast, lean webpage that even loads quickly on mobile devices. At the end of the message you’ll find the number of times the page has been viewed in addition to how long ago the message was posted. That’s it. No flashy videos or bulky images… just the message you wanted your readers to see.
I’m hoping to see some of the third-party Twitter clients integrate with a.longreply.com because I love how clean it is, but I don’t mind visiting the homepage for the few times I need to bust out of the 140 character barrier.

I think services like this are great, if used properly. I would only CONSIDER using this if someone wanted advice that didn’t fit in 140 characters. They asked and I wanted to provide a clear response.
Also take a look at [runt.ly.] It is another simple way to share more than 140 characters, that has a few upgraded features like wysiwyg editing and embedded photos and videos, but still loads fast on mobile devices. Has a few nice features, not too much.
I built an app that lets you post longer than 140 characters called [tweetc.com.] It will also let you post by email and auto embed links :
Have you heard of Twextra? [twextra.com] – It lets you post large, rich text messages (max 100,000 characters) on Twitter or LinkedIn