Yahoo Pipes

What is Pipes?
Pipes is an interactive tool that enables you to combine many data feeds, like RSS, into a single aggregate. It is a free online service that lets you remix popular feed types and create data mashups using a visual editor. You can use Pipes to run your own web projects, or publish and share your own web services without ever having to write a line of code.

Building a Pipe
You make a Pipe by dragging pre-configured modules onto a canvas and wiring them together in the Pipes Editor.

Each Pipe consists of two or more modules, each of which performs a single, specific task. For example, the Fetch module will retrieve a feed URL, while the Sort module will re-order a feed based on criteria you provide (you can find a complete list of available modules in the documentation.)

Each module has one or more terminals, represented by small circles in the interface. You can wire modules together by clicking on one module's output terminal and another module's input terminal. Now the output from the first module will serve as input to the second module.

In addition to data feeds, Pipes also lets you add user input fields into your Pipe. These show up at runtime as form fields that users of your Pipe can fill in.

Sharing a Pipe
Once you've built a Pipe, you'll be able save it on our server and then call it like you would any other feed. Pipes offers output in RSS 2.0, RSS 1.0 (RDF), JSON and Atom formats for maximum flexibility. You can also choose to publish your Pipe and share it with the world, allowing other users to clone it, add their own improvements, or use it as a subcomponent in their own creations.

Hosted Pipes
A Hosted Pipe is a web-based interface that Pipes provides which allows you to execute a Pipe that you or someone else has built and published. It's a useful mechanism for quickly determining what type of content a Pipe outputs. It is also a jumping off point for subscribing to a Pipe in your favorite feed reader, viewing how the Pipe was constructed, or cloning it so that you can further tweak it yourself.

Check it out at http://pipes.yahoo.com