Here is a new API from google, worth looking at. We have done considerable work on google maps and Search API for web integration

Google hopes to increase its slice of the social networking pie tomorrow with an announcement of OpenSocial, an API that taps into social networking sites like LinkedIn, Hi5, Friendster and its own Orkut. The API is intended to do for these sites what Facebook's API has done for it: to increase the reach and penetration of social networking into users' lives, enhancing the availability and immediacy of social networking services.