Google entered into Open Social

Open Social enables the users to build applications which keeps you to communicate with your friends in the network.It makes easier for social networking,by building apps with API and java scripts.There are several sites which gives this facility,now google marched into social networking with open social.So you can create your own apps to meet social network's friends and update the feeds.
Open Social technology is implemented by google's gadget technology.So it is free to use and implement.Open Social will give common standard APIs to build applications.For developers to get started it has given limited orkut sandbox to build applicaiotions.
To get started(recommeded for developers who know java scripts,HTML,PHP,Java,Ruby etc) signup for open social, check this link.

http://code.google.com/support/opensocialsignup

To know more about Orkut's sandbox

http://code.google.com/apis/orkut/