Have you ever noticed those blogs that seem to automatically generate content? Typically they are done in good taste, maybe linking to a small portion of one of your posts and providing a link to the source. There are a few ways to accomplish this with WordPress, with one method being the free WP-o-Matic WordPress plugin.
This WordPress plugin allows you to add/import your feeds and sort them into campaigns and categories for easy management. You can then automatically generate posts from the feeds of your choice. Additional features include the ability to relink specific words as well as rewriting words within posts.
WP-o-Matic is actually a pretty well done plugin, but has the potential for abuse in the wrong hands. I recommend people that download this plugin use it responsibly and always only post excerpts of others works and provide a link to the source.