FeedWordPress is an Atom/RSS aggregator for WordPress by Charles Johnson thatt syndicates content from feeds that you choose into your WordPress weblog; if you syndicate several feeds then you can use WordPress’s posts database and templating engine as the back-end of an aggregation (“planet”) website. It was developed, originally, because I needed a more flexible replacement for Planet to use at Feminist Blogs.
FeedWordPress is designed with flexibility, ease of use, and ease of configuration in mind. You’ll need a working installation of WordPress or WordPress MU (version 3.0 or later), and also FTP or SFTP access to your web host. The ability to create cron jobs on your web host is helpful but not required. You don’t need to tweak any plain-text configuration files and you don’t need shell access to your web host to make it work.
Download and info: http://wordpress.org/extend/plugins/feedwordpress/