Intellij Idea Keyboard Shortcuts

First, go to the source for keyboard shortcut reference cards for versions 8, 7, 6, 5, and 4.5, on Windows, Linux and Mac:

in IntelliJ IDEA, select "Help -> Default Keymap Reference". This displays the appropriate PDF.

http://www.jetbrains.com/idea/documentation/documentation.html = "IntelliJ IDEA 8 Developers Documentation"
- Select (click on) the appropriate version on the left, then download and print the appropriate "Keymap" for your operating system platform.

Other references:

Other useful keyboard shortcuts:

Ctrl + Shift + {Up or Down Arrow} = moves lines/methods up and down in the source code.
Ctrl + Shift + A = "It does a search as you type through all the commands in intellij. Not only that but when you find the command you want it also displays the corresponding shortcut key next to it!" -- http://stackoverflow.com/users/42491/montyontherun
Ctrl + Shift + T = go to test package (or class under test, from test class)
Ctrl + F12 = "File Structure Popup" -- like the Eclipse Outline View.
Ctrl + H = "Type Hierarchy" view = shows a tree of parent and child classes of this class
Shift + F7 = "Smart Step Into" (in Debug mode) = with multiple calls on the current line, it displays a popup of calls that could be made, highlighting by default the one that you're most likey to want. (Works well if you're mostly not interested in debugging getters. ;-)