Yahoo Pipes is an interactive feed aggregator and manipulator that can remix popular feed types and create data mashups using a visual editor. You can use Yahoo Pipes to run your own web projects, or publish and share your own web services without ever having to write a line of code.
Why is it called Pipes?
The name pays tribute to Unix pipes, which let programmers do astonishingly clever things by making it easy to chain simple utilities together on the command line.
Browse Pipes and find those that are most frequently run. To get a feel of the power of Yahoo pipes, I suggest you try Aggregated News Alerts, by DanielRaffel that gets news from Yahoo!, Google, MSN, Findory, Bloglines, and Technorati on any topic, all fed to you in one feed!
How will you use Pipes by Yahoo! We used it to Join, Split, Cut, Sort, Mix, Mash Multiple RSS Feeds
Update: Yahoo Pipes in now discontinued.