How to Yahoo! with Flash & Flex
Yahoo! has a set of tutorials in their Flash Developer Network
The tutorials include
• performing a Yahoo! Search with ActionScript 2 and 3
• embed a Yahoo! Map with ActionScript 2
• create a Yahoo! Music Jukebox plugin
• create a mash up of Flash and upcoming.org
The Yahoo! Maps API is very well documented and they have a ton of cool examples in their Maps Application Gallery, including a video tour of San Francisco.