Philipp Lenssen's just posted to say that Google's bought Jaiku.
Jaiku talk a lot about "presence sharing" and Philipp succinctly translates that as "your friends know where you are & what you’re up to by looking at their cell phone using Jaiku’s service". This is very much the same arena that dodgeball played in - before the founders quit Google.
So what are Google up to here? There are no mobile community leaders yet. There's no mobile gathering site that's similar to what YouTube did for video or what LiveJournal did for early blogging. Google is betting there will be a mobile community market leader. Google is betting that we'll all become addicted and that we'll all spend hours each week on our mobile keeping up to date with the mobile community. Google want to make it as easy as possible for that community to happen and they want to place appropriate adverts in the community to help fund it.
This is an area where, I suspect, the savvy mobile operators (the likes of Vodafone and t-mobile) will be unwilling to surrender to Google without a brawl.
We've even seen Nokia plan a future around this sort of mobile content community. The Register reckon Nokia is doomed to fail here. No one will be willing to pay for mobile content in the long term (which is why we're likely to see Google go on an ad funded model). The Register also predict that the operator networks will fight the phone makers in the pay-for-mobile-portal arena and charmingly use the phrase "two bald men fighting over a comb".
A good question for any Search Marketer to walk away with today is "Is content really king? Or is communication king?" ... if mobile takes off then it's likely to be on the strength of easy communication rather than strong content.