Google Inc. continued its acquisition spree with the purchase of Jaiku Ltd., a Finnish company that offers a social-networking service similar to Twitter.

Jaiku describes the service as one that lets users share their "activity streams," which it defines as "a log of everyday things as they happen." An activity stream can include recommendations, details of events the user is attending, photos and questions. Users can post new items online, via instant message and on mobile phones using text message.

The companies did not disclose terms of the acquisition, which is closed. With the announcement, Jaiku closed new user registration but will still allow existing users to invite friends to join. Current users can sign up for an invitation to participate in the testing of new services to come, Jaiku said on its Web site.

Jaiku also offers a mobile feature that allows users to view items posted by friends in the list of contacts on their phones. Mobile users can also opt to share availability status, location and calendar items with anyone else or with selected contacts. The capabilities are available to owners of Nokia Corp. phones running Series 60 software.

In a blog posting, Google wrote that it is interested in Jaiku because the application can help busy people stay in touch with other people, whether they're at a computer or on a mobile phone.

Jaiku was founded early last year and the service launched in July 2006. The company is based in Helsinki.

Google has made many acquisitions, large and small, over the past years. Some recent buys include Postini, Panoramio and YouTube. Just two weeks ago, Google bought mobile social-networking company Zingku Inc. amid rumors that the search giant may be developing a mobile phone.

The IDG News Service is a Network World affiliate.