Aside from the history which @ritrzblok has provided, I can answer as a regular and dedicated Twitter user. I do think just 10 more characters would let users be a lot more creative with their Tweets, and I would love it. But do I think they should do it? No way. All that is going to happen is that instead of complaining about 140 characters, users will complain about 150 characters, about 200 characters, or about any other limitation. This is all part of Twitters uniqueness. Give users a higher limit and it’s just like any other messaging site out there.

There are plenty of services out there to add on to the length of a Tweet, such as TwitLonger which is more or less a blog which posts the first few words and a link to your Twitter. Many other blogs will let you do the same thing, and even do it automatically, such as Posterous. These exterior sites, because of linking, will let you perform any function you want. There are TONS of these services out there!

If you really need an extra 10, 20, or 50 characters, I don’t think anyone would oppose to you adding a second tweet. If it’s more than 280 (two tweets), it’s no longer a micro-blog (which is what Twitter calls itself), it’s a full blog, and there are plenty of other free services out there you can use to share your full thoughts and then use the link on Twitter, whether to share publicly, or directly with a friend through the use of a mention.

So while I would love the 10 character increase for more flexibility, it’s not hard to condense your thoughts after you practice it, or learn that it’s OK to tweet twice or use an external service, so I don’t think it would be good for Twitter.

With 10 extra characters I'm sure that there can be alot more said. However, the history behind the character limit explains how Twitter came up with their short message concept. When texting first broke ground and emerged, carriers limited customers to 160 characters. Following in the short message trend, Twitter wanted to stay within this type of a limit. Although 160 would have been ideal, Twitter creators also wanted their users to be able to include their user names within the tweet. To do this , they needed to decrease the number of characters allowed and settled on 140, providing 20 for Twitter usernames.