Flex 4 Fun is the authoritative guide to graphics and animation in Flex 4 (i.e., the fun stuff). It is written by Chet Haase, who was an engineer on the Adobe Flex team during the development of Flex 4 and coauthor with Romain Guy of Filthy Rich Clients. The book is filled with insightful tips on user interface programming and includes nearly seventy example programs written expressly for the book that demonstrate the concepts presented in the text.

You can check out a sample chapter for Flex 4 Fun here:

http://www.artima.com/samples/flex4funCh2.pdf

You can get more information and purchase the book here:

http://www.artima.com/shop/flex_4_fun