Guttershark is an Actionscript 3 Library for Flash Developers. Guttershark provides the “scaffolding” for 95% of Flash based websites. Guttershark provides you with many default things, like preloading, bandwidth sniffing, cpu sniffing, remoting, site xml file, etc.
Guttershark provides a default DocumentController - you opt into default functionality by using FlashVars and it provides hooks into a startup sequence with all of these default options. As well as a ton of utility classes for many common things.
All examples can be found in the google code SVN repository.