i have the following directories:
-UI
-BusinessLogic
-DataAccess
-BusinessObjects
if i have a class that is a client stub to a server side service that changes state on a server system, where would that go . .
this code belongs in the recycle bin ;-)
seriously, if you wrote it and don't know where it goes, then either the code is questionable or your partitioning is questionable; how are we supposed to have more information about your system than you have?
now if you just want some uninformed opinions, those we've got by the petabyte:
it would be more helpful if you told us what the stub actually does; without specifics it is hard to know where it belongs, and/or it is easy to argue in a vacuum about where it "should" belong