IOS:

I often wondered about why Mojang never added a bluetooth multiplayer mode (until now). But now I know how to play without wlan! Download a app which is playable per bluetooth (we're using lightbike 2, you can get it for free in the apple app store) then play about one minute with the friend(s) you want to join the game. After that quickly switch to the pocket edition open your map and turn it to visible. Now your friend can join!