Twitter made a big announcement today on their blog. They’ve just crossed one million registered applications, built by more than 750,000 developers. When you compare that to just 150,000 apps a year ago, you can see what a huge increase that is. They also said that a new app is registered every 1.5 seconds.

Because Twitter wants to enable developers with all the right tools they need, they also announced a Twitter developer site. The site allows people building apps that integrate Twitter to keep in contact with team members, as well as exchange ideas with other developers.

Twitter went on to say that “more than $500 million has been invested in ecosystem companies, and more than a billion dollars has been paid out in acquisitions”.

If you are looking for some examples of companies using Twitter, the posting gave a good list of who and how they are using it. From Mass Relevance who combed through thousands of tweets to bring us the first Twitter Town Hall to Poptweets who created the iPhone game where you can match tweets with the famous people who said them.

It seems Twitter is doing everything they can to provide just the right platform for developers.