This addon gives a different page title for your site when someone visits your homepage vs. the rest of your photos to help with SEO. This makes it seem to search engines that you have a home page with a different title tag format than the rest of your site.
Installation: Put page_title.php in your addons folder and then put <PAGE_TITLE> in the title tag on the image_template.html file. This addon requires version 1.7
How it works: When someone visits your site the page title will be SiteTitle | SubTitle | URL
When someone visits any other image, the page title will be ImageTitle | SiteTitle | URL
You can see it work on my site at http://blog.kevincrafts.com/
Version 1.2 - Thanks to massin for refining the code a bit to work where your install is not at the root level.