The Content Analysis module can help cross-reference information from one feed to items in another feed. Some Source modules, like Flickr, Yahoo! Search, and Google Base, use keywords to drive their searches.
This example fetches a news feed and pipes it through the Content Analysis module. The feed is then piped into a For Each: Annotate module containing a Yahoo! Search module. With the two feeds wired together, we can use an element from the news feed - in this case item.y:content_analysis - as the text to search for.
The For Each: Annotate module adds a new element to each feed item. The new element contains the first matching item from the Yahoo! Search. So if our first new item was "Pioneering treatment for brain cancer gets Swiss approval", then its y:content_analysis value, "brain cancer", becomes the Yahoo! Search module's search term. The first search result item is inserted into the original item as an element we name "xref".
Finally, we pipe the resulting feed through the Regex module, using data from the Yahoo! Search result to append the cross-reference title and link to the end of the original news feed's description element.
Pipe Web Address: http://pipes.yahoo.com/pipes_team/CsaQgONS3BGc_r4pLe2fWQ