<<Disclaimer: Verify this information before applying it to your situation.>>

Thank you all who responded to my query.  Here are the responses:

I use pearled Jowar and get great results.  I make tobolleah (I don't
know if I spelled it right) and the results are great.  Just follow the
cooking directions on the Jowar package.

There is a product called Riccous (sp?).  It comes in a box, is made w/
rice, & is available at health food store.  The manufacturer may be
Fantastic Foods, or a natural/health food company similar to that.
Might want to check manufacturer lists (either on this site or at
www.celiac.com) to see who has it in their inventory.  A member of our
group had tried & like it.  Good Luck.

I have used RizCous (from Lundberg) as a substitute for couscous, but it
does still sorta taste like rice, not nutty like couscous.  I have
gotten it at Fresh Fields/Whole Foods.

Since it so rice-like, why not go back to the original and use rice?

I think kasha might work as a suitable substitute.  It's buckwheat
groats.  I love it.  I've had quinoa but wasn't crazy about it.  Haven't
tried Jowar.  But to each his own...

I use pearled Jowar and get great results.  I make tobolleah (I don't
know if I spelled it right) and the results are great.  Just follow the
cooking directions on the Jowar package.

I use either millet or quinoa as a couscous substitute.  I think millet
has the texture which is most similar to couscous itself.  In the
recipes I use the couscous is cooked separately anyway, so substitution
is easy just by adjusting the timing to suit.

I have taken dry rice and chopped it in my blender.  When cooked it
resembles couscous.  This is what I use for my filler in meatloaf and
stuffed peppers.  My family thinks it is fine.  Hope this suggestion is
helpful.

I use quinoa in place of couscous.  Very similar in taste, texture and
cooking time.

In my opinion, millet is the closest thing to couscous that I know of; I
am a very sensitive celiac and never have had a problem with millet.
Hope this isn't too late for your weekend.

Quinoa Tabouli Salad (from Susan Mercier)

Measure out 1 1/2 Cups quinoa and rinse it very well.  Drain in a fine
sieve.  Add quinoa to 3 cups boiling water, cover and let cook on low
for 20 minutes until dry looking, turn out into a bowl and chill.

When cold, ADD:
3 Cups finely Chopped Parsley
1 large diced English cucumber
3 Cups chopped tomatoes
1 medium diced red onion (Optional)
1 small chopped green pepper
1 stalk of celery, diced

Mix well, breaking up any clumps of quinoa, dress to taste (dressing
recipe below) and serve.  .

Dressing:  Mix together
1/4 cup extra virgin olive oil
1/2 Cup fresh lemon juice (or bottled)
1 tsp dry mint leaves
1/2 tsp salt
1/4 tsp pepper

Keeps well in refrigerator for several days.  Delicious served with corn
chips.  Hint:  I do most of my chopping in the food processor (it goes
quicker) either by using the chopping disk or blade.  If it is too
chunky, then the effect of the salad is lost.  I usually add all the
dressing, as the quinoa soaks up the flavor.

Take care, Sarah in Washington, D.C.