I'm using the trial version of Photoshop CS5. Well you can download it on adobe.com. You must have an Adobe ID to download it. Install it and open it. It should look like this:
Step 2: Open your panorama
Next, open you (crappy) panorama picture.
Step 3: Fill-in the blanks!
First, use the Magic Wand tool and select the black part of the picture. Then press the Delete button. Once a dialog box appeared, select "Content-Aware" and press OK. That "Content-Aware" function in CS5 is not present in other versions of Photoshop. Just wait.
Step 4: You're done!
It's done! Now you can fill out the missing parts!