If you already have a background in each of Ruby ,Python, Haskell and Haskell you probably can learn a good chunk of Clojure in a weekend, as it shares many features with these languages. The main difference, of course, is the prominence of lispy prefix function calls delimited by parens. Well, and macros, but Ruby does some of this.

Some links: http://blog.fogus.me/2010/06/09/clojure-rb/ http://stackoverflow.com/questions/4509782/simple-explanatio... http://jkkramer.com/sudoku.html