Nintendo and mobile service Docomo will begin offering 3DS tethering for select Android phones beginning today in Japan. The Kantan Tethering app will be available in the Google Play store to allow 3DS users to get online with their phone.
Too bad it only works with Samsung's Galaxy S5 right now. The app will come to various Xperia and Aquos phones later this year.
Tech in Asia reports that the app is free, though it'll use your mobile's data as normal. It uses the WPS protocol to make things easy on those that don't quite get network configuration.
Bonus: users that fill out a related survey get a download code for an upcoming, unannounced Virtual Console title.
I'd use this all the time if it were available here. I already almost kill my monthly MiFi plan playing Vita and 3DS games over a WiFi connection.