Hello,
I'm using the Java SDK 1.4.1_02 for Java and omniORB 3.05 for C++
The Java program is both a client and a server.
The C++ progrma is both a client and a server.

When I invoke a method on a remote object, it can block indefinitely.
How can I set a timeout?  Or otherwise force control to return to the
calling program after some period of time (60 seconds?)

The best answer will detail a solution for both directions...
Java client -> C++ server
C++ client -> Java server

Will do Java client making call and client will continue after recieving
result or after 60 seconds.
  Prototype will not have any CORBA. There will be just call to foo()
function which can return result or hang.
  You should specify what to do if 60 seconds expire in the middle of
recieving result.

Asking 55$.

I think, the server should take care about rejecting requests that
hang the processing thread it for an unlimited time. Otherwise it is
very sensitive for the malicious attack. The task-specific method that
handles the invocation could just verify the parameters first and
throw something like BAD_PARAM or NO_RESOURCES, probably with some
specific minor code set.

As far as I know, there is no standard way to set the socket timeouts
for each CORBA request. In GNU Classpath CORBA your problem would be
reduced into setting the properties
gnu.classpath.CORBA.TOUT_WHILE_READING,
gnu.classpath.CORBA.TOUT_AFTER_RECEIVING and
gnu.classpath.CORBA.TOUT_START_READING_MESSAGE.