There are numerous ways out there to get a new background look, including actual cloth. But how would you like to do it quickly and easily and FREE!? Here's my tutorial on how I achieve different backgrounds when i'm limited for space, want to have a different look or I don't like the original.
First, search Google for FREE wall textures. Here is where I got mine:
http://www.freestockimages.org/2009/05/13/free-stock-images-part-15-stone-wall-textures-continued/
Then open Photoshop. Open your original image and your texture. Drag the texture over the original image, be sure your arrow tool is selected. You may have to resize or move the texture around to achieve how large you want the backdrop to look. This photo is my original.
Then, you lower the opacity of the texture enough to see the original photo. Click on the erase tool, making sure you have selected a brush size with a feathered edge. Erase the texture off of the areas of your subjects you want to delete. Then raise the opacity to original so you can see what the final will look like. You may have to do that step a few times to be sure the edges do not look odd. To clean up, I click on a no-feathered brush edge to give it a clean edge.
Once you've done that, flatten your image, run an action or leave it and you're good to go!
Below is the new background! Have fun creating!