Based on David Stinemetze's MergedRSS Class

If you ever wanted to have a Zenphoto RSS that for example returns latest images for album x but latest albums for album y this is the tool to use. Just enter the urls of the seperate feeds and it will return the combined feed.

The merged feed is called by yourdomain.com/index.php?mergedrss

While this plugin is meant for Zenphoto's RSS feeds, you could also use even external RSS feeds. But be aware that hijacking content may be a vialation of applicable laws!