This is the discussion topic for the Feedgrabber extension.
The Feedgrabber extension lets you 'crawl' one or more external RSS feeds, of which the items will be added to your PivotX as seperate entries. You can use this for when [[feed]] is too restrictive to use, or if you want to show the items from the RSS Feed as 'regular' entries on your site.
Get the extension here: http://extensions.pivotx.net/entry/10/feedgrabber.