Nowadays it really difficult to find free niche or idea on first sight. But guys from San Francisco did it. In March 2006 they did prototype of Twitter and launched it publicly in August of 2006.

It was really nice and simple idea. Twitter asks one question, “What’s happening?” Answers must be under 140 characters in length and can be sent via mobile texting, instant message, or the web.

But if you are developer most of time on your job happening code producing. And some times you need to share it with your teammates and debug together.

Sharing code around on the Internet can be a pain sometimes. Social networking sites have limits on post size, not all forums support the same language tags, making code accessible to everyone can be a problem.
Sometimes a nice, neat and tidy URL for your code can do wonders. This is known and solved issue in web by pastebins.

Here is example:

Of course there are some special pastebins for Twitter. There are some pastebins which exist specifically to surpass character limitations of microblogging services like Twitter. The idea is to save a large piece of text in a pastebin and post the URL and text excerpt to microblogging services which have character limitations.

Most known is txtb.in

Past.

Press button and Tweet.

There are a lot of common edges in social networking, bookmarking and pastebins. And Twitter is a result of combining of them.