Google have introduced a new instant message service Google Buzz, as part of their Gmail email service. It has a more complicated looking interface than Twitter, and some of the features of Foursquare and Facebook. But what I found most interesting is that it seems to adopt some of the fetures of Google Wave, but with a much less complicated interface. It seems to be very fast, even on my slow wireless link.
You can "follow" other Buzz users, so you see what they post. Your postings can be public or provate. Also you can easily attach a web link to the post. The linking works much better than Twitter or Facebook. In Twitter you paste in a URL and hope it works. Twitter doesn't check the address goes somewhere. In Facebook the system goes and gets a copy of the whole web page and displas a portion, which can take some time it. Buzz falls somewhere in between, replacing the web address with the title of the web page. This goves you the reassurance you have the right page, without clogging up your screen.