I'd like to be able to sort galleries (albums) within a subcategory or category by Title or any other attribute.
Is there a way to do this via the web interface or the API?
In regards to the API, that's the most recent information I could find on the subject:
(link to Dgrin thread)
So unless there has been a recent addition to the API that I missed, it's not possible via the API at this point.
That said, you can do it via the browser. Just make sure that the galleries / gallery categories box on your homepage is set to "position" and then you should find an arrange link at the top of the box on your homepage, any category and subcategory page, allowing you to arrange the items. Within the arrange tool, you should also find the "quick sort" feature that lets you choose from date and title options. For more information, also check out the "arranging galleries" section.