For Christmas, Lisa received a wireless mouse. She wanted something to contain the mouse and the USB connector so they wouldn't become lost or damaged.
As it was, I had just come across a nifty craft blog, Pin and Paper. While I was perusing the blog, I saved one of the entries: the creation of a cute little flat-bottomed, zippered pouch. It occured to me that this little pouch would be a good home for the wireless mouse & connector.
Although I measured the mouse, I was concerned that the resulant pouch might be too small (as what happened when I made a holder for my digital camera), so I used the measurements as mentioned in the tutorial. The pouch turned out to be just a little too big, but better that, than too small and unuseable. I added a small interior pocket for the USB connector, as Lisa didn't want the connector banging around next to the mouse.
The machine embroidered letter came from Designs by SiCK, the Cheese and Mouse Font.