I use screen (probably less often than I should) but can never remember what the keyboard controls are. A wonderful gentleman by the name of Carlos Fenollosa has created a truly wonderful cheatsheet that shall now adorn my office wall: http://cfenollosa.com/misc/screen.pdf
For those of you that don’t know what screen is, it is a way to run shell prompts on a Linux machine, that stay running even if you disconnect. You can also have multiple shells running, and switch between them. You can even run them in split-screen, and see two shells at once! Life is good.