Mashups are a fascinating and useful way to explore the "deep web". A mashup pulls in data from other websites to create a view of data greater than the sum of the parts. An article just came out today in InformIT called Mining the Deep Web with Mashups that explores mashups from a current perspective. The author, Michael Ogrinz, has just published a book: Mashup Patterns: Designs and Examples for the Modern Enterprise And, there's a website called "Mashup Patterns". Google has released a Mashup Editor to a limited number of developers. I've experimented a bit with Yahoo Pipes. Here's an example I made integrating map data with Flickr. The possibilities go on and on. If you're working with mashups, I'd love to hear about it.