[CFCDev] Service Layer?

[Jeff D . Chastain]

I am working on a simple contact manager type application using MG Unity and some other things I wanted to play with.  I have built all of my low level data objects (bean, dao, gateway) for a Contact, which has one or more Addresses, which then has a State and a Country.

Where I am getting stuck is on the "service" layer.  In once case, I am looking to create functionality where an entire contact could be updated at once by passing in a struct (i.e. the form scope).  So in my mind this means a ContactService with a method to update the contact and that method then utilizes the different contact, address, state, and country beans and daos. 

Another requirement though is to obtain a list of the 5 most recently updated contacts.  Is this something that would go in the same ContactService or where would this go?  I have never had a good grasp on what should go where in terms of a service layer, so I am looking for any input on how service layers are really built and organized.

Thanks
-- Jeff