Jaiku, the activity streaming and presence service (also referred to as micro blogging), has been acquired by Google. The terms of the acquisition has not been disclosed. While Jaiku is often used via the web it also has strong mobile features (including a native S60 client) and the idea of presence is a very important part of the Jaiku message. 

The Jaiku S60 client can theoretically be used to replace the Contacts program (although until Jaiku has a larger user base the benefits of doing so are questionable). It also enables automatic broadcast of presence information (based on your availability as set by Calendar and current Profile information) and allows you to read and update you activity stream (short messages telling people what you are doing) and read and respond to your friends activity streams. Hopefully Jaiku will continue to use S60 as its platform for innovating its mobile offering.

The micro blogging phenomenon has taken off in a big way over the last year or so. Jaiku's best known competitor is Twitter. Twitter is a less fully featured version of Jaiku, but has gained greater (relative) traction in the US thanks to its use among popular bloggers.

Both services encourage users to update their activity stream which short snippets of information about what they are doing (e.g. drinking coffee at the North Pole). This information is then shared (publicly or privately) with friends (contacts). Thus you can follow the activity of your friends and hence there is a strong social element to the services.

While it is the activity stream that has gained Jaiku most attention the more interesting concept is that around presence. While clearly an activity stream is part of presence the ability to know whether someone can be contacted conveniently is potential even more useful. Presence has long been used in instant messaging clients, but thes ehave largely been tied to PCs rather than too individuals.  

Jaiku was always a likely candidate to be acquired by a bigger company, but the time scale may take some by suprise.

There's plenty of room for potential future directions for Jaiku. The core product will continued to be developed and could grow to encompass more presence information (e.g. location from GPS or via cellular tragulation). There's also a lot of potential to integrate Jaiku with existing Google products such as GMail, Google Talk or Grand Central (both of which could benefit from strong presence features) or use existing Google expertise to improve the current user experience (e.g. searching activity stream with Google search technology).

Here's a message from the founders:

Jaiku is joining Google. While it's too soon to comment on specific plans, we look forward to working with our new friends at Google over the coming months to expand in ways we hope you'll find interesting and useful. Our engineers are excited to be working together and enthusiastic developers lead to great innovation. We look forward to accomplishing great things together. In order to focus on innovation instead of scaling, we have decided to close new user sign-ups for now.

But fear not, all our Jaiku services will stay running the way you are used to and you will be able to invite your friends to Jaiku. We have put together a quick Q&A about the acquisition .

Jyri Engeström and Petteri Koponen, Jaiku Founders