relevant exercises from one of scalaz' authors

http://blog.tmorris.net/lifting-haskell-addendum/

http://blog.tmorris.net/lifting/

and the applicative functor and following chapters in Learn you a Haskell (it wasn't real easy to navigate scaladocs, source, etc. Some folks used to just hoogle and then look for the same-named scalaz method

http://groups.google.com/group/scala-user/browse_frm/thread/...

and the scalac switches -explaintypes, -Ytyper-debug are kinda helpful.