Great! Worked like a charm, thanks!
I don't mean to push my luck here but would you mind telling me what the name of the variable is that holds the category (within showphoto.php)? I would like to make it something like "alt=\"$filename - $categoryname\" so the ALT text would end up, for example, as "Chihuhuas Meeting Great Danes. - Chihuahua" as opposed to just "Chihuhuas Meeting Great Danes."
Thanks again for your help.
Edit: Oops! I just realized it looks like the change you gave me is putting the actually file name (minus the .jpg) as the alt text - is there a way I could use the page title instead? That is, the short descriptiono of the photo the user entered when uploading?