Google has joined the check-in revolution with the introduction of check-ins to Google Latitude. The only odd thing is that it has taken the company so long to do so. The service is available initially for anyone using Google Maps V5.1 for Android. Latitude currently has 10m users a month.

According to a Google blog post, users can still use Latitude to automatically update and share their location, but check-ins let them add context to the location. So instead of your friends being able to see you are in a particular part of town, they can see that you’ve checked in to a particular bar or restaurant. 

Google has also added what it calls “a few twists”. Notifications (which you can turn on in Latitude’s settings) give you a notification to check in at a nearby place once you arrive. Handy if you’re the sort of person that heads for a restaurant, stands outside for two hours, then goes home hungry because you forgot to go in. Automatic check-ins check you in automatically at places you designate. And once you leave a place, Google automatically checks you out.

Google is also offering Foursquare style badges of honour. User can achieve ‘Regular’, ‘VIP’ or ‘Guru’ status at places they check into. With one eye on the privacy lobby, the blog posts notes that checking in is 100 per cent opt-in, and users can choose to share any check-in with your their on Latitude, publicly on the web and their Google profile, or just themselves. Users can also see their complete history of check-ins using the optional History tab at google.com/latitude from their PC.

Comments on the blog post suggest not everyone is thrilled with the new service, however. Users in Romania, Ireland and Russia claim they can’t access it, while another says: “Youre missing Facebook/Twitter crossposting to pull people into Latitude. Isolation makes it another Orkut”.

A couple of people complain that the system only lets them check into venues that are already on Latitude and ask for the ability to create their own, and one commenter laments the fact that “there are places that are listed on Google Maps in my browser that are not available as places to check in on my mobile phone. Ironically, this seems to include most places that I would normally be wanting to check in at.” He adds that these are all places that are supported by Gowalla, Foursquare and Facebook, and concludes: “This seems like another field Google has jumped into and squandered their opportunity to make a really good first impression with some polish and cool social aspects.”