Koornk takes more personalized approach to micro-blogging, but still looks an awful lot like Twitter. The site and users’ activity streams are organized by personal information, such as interests and geographic location, to make connections between new members.
 
The site aims to be global, but is still at such an early stage that it is difficult [...]

near.ly tracks news articles and blog postings that are sent from 1,000 feet from any address in the United States and sends them, via Twitter, to you so that you can keep up with what is happening locally.
Sign-up at the near.ly home page and enter your address and Twitter login information (username and password). After [...]

BrightKite delivers placestreams and friend alerts

BrightKite takes the idea of recording all sorts of activity, from text notes to pictures of events and people, and applies it to places. The result is called “placestreaming,” though BrightKite keeps the orientation on people rather than places: what you are doing, what’s going on around you, and what [...]

We haven’t finished our review of Plazes, but that shouldn’t stop you from adding your own in Comments right now!

Dopplr lets you keep track of when you and your friends will be in the same city. The service is easy to use, requiring only familiarity with online calendaring, and makes connecting with others simple. Members can invite members using email, by importing their GMail, Hotmail, Yahoo! Mail, LinkedIn, Twitter, Flickr and Facebook contacts, or by [...]

Jaiku was an experimental invitation-only micro-blogging site that was acquired by Google and operated until January 2009, when it was discontinued as part of cost-cutting efforts at the company. Google has said it will give the underlying code to anyone who would like to use it, but no longer supports posting to the site. 
If you were [...]