Every webmaster thinks why I have not been able to make s site like twitter. It is possible to have micro blogging sites at of your own. The open source script StatusNet can help you in achieving this goal
StatusNet is the open source micro messaging platform that helps you share and connect in real-time within your own domain. With StatusNet you can encourage collaboration, build and engage your community, and be in command of your brand.
If you want hassle free micro blogging site just sign free hosted version of this script. Well it is process of testing but you can still book your name or brand for future