What is the IntelliJ shortcut to create a local variable?

IntelliJ 13.1 introduced Postfix completion.

With Postfix Completion you can introduce a local variable by typing:

MyObject.getValue().var

and pressing ctrl + space or enter.

It even works inside other statements. For example:

foo.someMethod(myObject.getValue().var);

for mac users: alt + enter at the position where you want to generate your variable

Yep! This is the Introduce Variable refactoring. By default, select some text, and then hit Ctrl + Alt + V (for Mac: ⌘+⌥+V). If the expression is incomplete or invalid, IntelliJ will still make a good guess about what you meant and try to fix it for you.