The Feedage.com RSS Blender will create an RSS Feed from any mix of Feeds. Create your favorite RSS Mashups -

Enter the Name of the Blend (Blend Name)
Enter up to 5 URLs of the Feeds you want to blend (URL)
Enter the number of stories to be included from each Feed (Count)
Click Save

This is what the feedage RSS blends end up like Here are the rss.stumbleupon links and their descriptions.

http://ping.fm/7Z3Rn

These are rss.stumbleupon favorites. The sites you thumbed up.

http://ping.fm/wuVfL

These are rss.stumbleupon reviews about the sites.

http://ping.fm/0H9Xf

See them live check it out here:
http://owl.li/62koZ