Oh, I see - your Services interface is not the one Sun defined for you, right? All right, you can define this how you want then. One possible problem with this definition though is the requirement
Keep in mind that networking must be entirely bypassed in the non-networked mode.
Now this isn't an exact requirement, but to my mind I'd prefer that my non-networked code avoid any mention of networking-related classes at all. Using an API that mentions "throws RemoteException" forces the client to catch RemoteException, which means the client has to know at least a tiny bit about RMI. And what if you want to change your networking to use sockets later? I'd prefer to insulate all other classes from any knowledge of whether networking is involved, or whether it uses sockets or RMI.
Now you could use Max's solution and declare throws IOException rather than throws RemoteException. That's a bit more palatable to me. Would make more sense if other IOexceptions were propagated this way, but Sun's interface makes this difficult. But that's another discussion...