I usually prefer money on servers since it's faster to develop for my team. But I guess for the functionally gifted, this is a great solution.
delayed_job, Amazon SQS, etc are not RPC systems. You can't block waiting on a response like you can with messaging systems.
For instance, delayed_job makes an RPC call that asks "how much disk space is this repository using?" It waits until it gets a response from an Ernie handler then continues with its background job.
Also, I found that a lot of concepts from Prolog carry over nicely. Erlang was initially implemented in Prolog, and that's where it gets pattern matching and immutable variables from. (Along with several stylistic / syntactic quirks.)