how to push a jar file to workers

[Daniel Mahler]

I would like to use json4s in my interactive spark-shell sessions.
I have tried adding the jar to $SPARK_CLASSPATH but it seems
that although the $SPARK_CLASSPATH is propagated to the workers,
the jar file itself is not.
Is there a better way to make a jar file available to all workers
than just rsyncing it individually to each worker?

thanks
Daniel