While these numbers are still relatively small compared to the total number of Facebook users (under 10%), it's huge for mobile social networking. Facebook has a really good mobile site and it looks like it's only getting better.

Facebook Mobile is now probably bigger than the entire userbase of Mixi, Japan's leading social network and a site that is very frequently accessed by mobile. Last week 6 leading Japanese social networks, including Mixi, MySpace Japan, Yahoo and others, announced that the companies are forming a mysterious alliance that could include content and widget sharing across their mobile sites.

We're curious how that kind of strategy will work compared to Facebook's strategy of building up a huge siloed web based social network and then creating a simple but extremely usable mobile version.

Commenting

It's interesting to see Facebook highlight the addition of commenting to its mobile interface. Non-users might not recognize what a big deal this is, but anyone who regularly uses mobile social networks (this authors' favorite is FriendFeedToGo) knows how frustrating it is to view but not interact with friends' content on your mobile. It's hugely liberating to be able to comment from your phone; it's a game changer, a feature that helps the technology move from not being worth using to being a pleasure to use.

It's early days for mobile social networking, but it's great to see market leader Facebook making great moves in feature development and user growth.

Thanks to the always-fabulous mobile blog Textually for bringing this announcement to our attention.