Meet PUB, the Programmable USB Button by simplicio - A USB device made with a PIC. I always enjoy PIC projects because, yes, I am a PIC enthusiast myself...
|PUB! is a Programmable USB Button on which you can program a sequence of keystrokes. When you press the button those keystrokes are "replayed" over a USB connection.|
The button (which is really a rotary encoder with a built-in push button switch) is programmed using an innovative and slightly quirky interface that does not require any custom software to be installed on your computer. All you need is a text editor like Notepad (for Windows) or gedit (for Linux).
The details for this project (to make one) are in this link.