I thought I would give it a try and love how it turned out. You can make your own too. I downloaded the chalkboard backgrounds from here. I put mine together in Photoshop but you can create it in Picasa just as well.
Simply open the chalkboard background in the color of your choice, then add your text on top. If you would rather, you can download mine and print so you can add it to your own Christmas decorations.