Yahoo! Pipes is a hosted visual programming environment and a cool one to boot! It provides a simple tool you can use to aggregate virtually any content on the web into an RSS feed without writing a single line of code.
The name Pipes is derived from the Unix pipelining function. For those unfamiliar with the Unix operating system, pipelining is a process of feeding output from one program as input for another. For the whole shebang, you can refer to this Wikipedia entry on Unix Pipelines.
Those who have attempted to programmatically perform pipelining of text data and convert them to useful RSS feeds could attest that this is not for the faint of heart. I’ve attempted this myself via the Nvidia Linux Display Drivers feed generation and it was hellishly difficult to get the useful data extraction process working. In the end, it worked, but I wish I had a tool like Yahoo! Pipes then to make my life easier.
Right now, the Nvidia Linux Display Drivers I had created is now broken due to changes in the originating NVidia web page. I might attempt to recreate that feed in Yahoo! Pipes some time soon
Jeremy Zawodny has an informative writeup on Yahoo! Pipes.