Scrolling within Screen's buffer

Since I keep forgetting this shortcut, here it is for posterity. Activating GNU Screen's scrollback feature can be done by pressing CTRL + a + [. This is especially handy when you are using Screen from within PuTTY.

While a number of sites provide additional Vim-esque shortcuts to navigate within the buffer, I've been able to get by fine with just the navigational arrow keys on my keyboard.