Apologies, soon after I sent my mail I managed to solve my own problem.
For possible future reference, the problem was that my disconnected
ethernet port had somehow decided to take up residence on the same
subnet as my wireless. The relevant parts of ifconfig are:
lo0: flags=8049 mtu 16384
I am using the system openmpi (1.2.3) on Mac OS X 10.5.6, gcc 4.0.1. I
believe these are all the standard tools.
If I mpirun as:
mpirun -n 2 ./a.out
Using the test code from http://www.boost.org/doc/libs/1_39_0/doc/html/mpi/getting_started.html#mpi.config
(note that at the moment I have not
