Packable lightweight Jacket

[Kaleidopete]

I bought one of these over a year ago and it's great. Packs up small and is lightweight. Not waterproof, but water resistant. Wind proof too. I like it so much I'm going to buy another one.

http://www.sportsauthority.com/ASICS-Mens-Packable-Jacket/product.jsp?productId=28711956

 

[Biker Dude]

North Face makes Summit Series jacket that is wind proof and water proof. It's more costly but it can fold up into a tiny little ball and give you all the protection needed.