How to save a copy of a multiplayer world in the new 0.7+ menus?

How do you save a joined game after the 0.7.1 update? The menus have all changed since 0.6.x and I can't find the option to save a copy of a joined world anymore. (My friend has got a diamond house on survival and I want to save it but it doesn't let me!)

Solution 1:

You can't. The menu option for this is missing from the new menus.

This might be a deliberate removal of the world-saving feature, or it might just be an oversight in the design of the new menus. Either way, you can't with version 0.7.0 or 0.7.1.

Source: Testing with two copies of Minecraft PE on 0.7.0 then 0.7.1.