Please not scala! I prefer to have clojure for android. Scala is too complex, to ugly, and tries todo too much. Its also to heavy for android (it needs tons of libs to run).
* As an aside, for beginner programmers I think that asking them to use a Lisp is far more conceptually challenging than using the basic syntax of Scala (could be wrong though... I don't know Clojure, but I found Common Lisp fairly easy to understand yet know that many beginners do not).