Focuswriter (sudo apt-get install focuswriter) is a full-screen tool in Ubuntu for distraction-free writing.
You can theme it like so, though I prefer the console-like green on pure black, monospace font.
@Lito: You need to install the package libsdl1.2-mixer to get typewriter sound effects because they are now fully optional.
Okay... so I try "sudo apt-get install libsdl1.2-mixer" but get package not found. https://bugs.launchpad.net/ubuntu/+source/focuswriter/+bug/897055
According to this bug report, it should just magically be fixed. And according to ubuntu.com, this package is in Precise.
Turns out the package is actually called "libsdl-mixer1.2-dev" for ubuntu. So "sudo apt-get install libsdl-mixer1.2-dev" and yay typewriter sound effects will load.
If you get a package not found error, run "sudo apt-get update" to make sure you have the latest packages. If you still don't see it, Ubuntu Sofware Center > Edit > Software Sources and make sure all the sources under "Ubuntu Software" and "Other Software" are checked.