Increasingly we've found agents for both buyers and sellers saying, "Just call my clients and work things out with them directly." Now, these aren't "list in MLS only" agents and they aren't (allegedly) discount brokers,and they aren't USes (Unrepresented Sellers, once known as For Sale By OhYouKnowWhos).
Yes, we've been able to get these transactions closed, and probably more expeditiously than if the agent WERE involved, but what's going on? Why are these agents abandoning their responsibilities? Because they have another job? Because they're lazy? Because they don't know how to proceed? Just because they can?
If you do step in, be very, very cautious not to take on agency by implication or agency by actions. Not only should you have them sign a Nonrepresentation Agreement with you, but you should be careful that your actions are consistent with this position.
If it walks like a duck and talks like a duck ... guess what?

As time goes by we seem to be weeding out this type of agent. I do like your no rep. idea. Never though about that and it does make sense.
Scott
How about the Buye's agent that stands in my own lobby and tells my office manager that she is calling my Seller to let him know the offer is there......My office manager explained patiently that the Seller was our client and we would call him as this agent whips out her cell phone and dials my Seller......(lack of training on her Broker's part).......it does grow old.........
Bill - it's just a CYA solution. Always reduce your risk when you can.
Scott - sooner or later non-productive agents get tired of paying their dues. Do protect against liability.
Julie - that a whole other scenario! Do you post your seller's phone numbers in the MLS? We never do. Of course that doesn't stop the agent who finds it in the phone book or online - though it does involve Ethics!