Mix any number of RSS feeds into one unique new feed!

RSS Mix: "You can then point a parser at the new feed and display a mix of stories from various sources on your website."

Create an RSS feed for any web page

Page2RSS: "
It is a service that helps you monitor web sites that do not publish feeds. It will check any web page for updates and deliver them to your favorite RSS aggregator."

Can I get site feeds for specific labels?

Blogger: "If a blog you read is using labels and also has site feeds enabled, then you can pick and choose which topics you want to subscribe to. The format for label feeds is this:
http://blogname.blogspot.com/feeds/posts/default/-/labelname"