According to Technology Review, it’s all about mobile phones.

The terms of the deal haven’t been announced, but regardless of Jaiku’s price tag, the purchase could be a significant one. Google has long been rumored to be working on a mobile phone, or “gPhone”; Jaiku was originally developed as software for cell phones, and one of the company’s cofounders, Jyri Engeström, was a product manager at Nokia.

While Google has refused to comment directly on whether it’s developing mobile-phone products, its activities over the past few months indicate that it is. Google has announced its intention to bid on a large swath of spectrum in early 2008; it has acquired a mobile-phone software startup, Android, based in Palo Alto, CA; and in a handful of public statements, representatives of the company have alluded to trying to make the mobile experience better. When asked for comment, Google referred to its public statement about the purchase: “Although we don’t have definite plans to announce at this time, we’re excited about helping to drive the next round of developments in Web and mobile technology.”

Hmmm… Pure speculation, of course.