I just got done reading Jeff Paries' book on Silverlight animation and I love it!!!  You should definitely check it out if you are looking for a cool stocking stuffer for the Silverlight coder in your life :)

http://www.amazon.com/Foundation-Silverlight-Animation-Jeff-Paries/dp/1430215690/ref=sr_1_1?ie=UTF8&s=books&qid=1229908663&sr=1-1

http://search.barnesandnoble.com/Foundation-Silverlight-2-Animation/Jeff-Paries/e/9781430215691/?itm=1