running a program with a different language than the current locale

[Jonathon Jongsma <jonathon jongsma gmail com>]

Does anybody know an easy way to run a program using a different
language translation than the current GNOME session (though this
probably applies to more than GNOME, it's just what I happen to be
using)?  for instance, say I want to run GNOME in English, but I want
to test out my gtkmm app by running it in portugese to see if the
translation works.  Is there a simple way to do this?  I thought it
would be as simple as setting a environment variable and starting the
app, but i can't seem to figure it out.

Jonathon