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

Here are some great suggestions!
-Deviled eggs, chocolate mousse cupss, mini cheesecakes made with nut crusts, apple slices dipped in carmel, nuts, choc. chips, etc
-Buy some of those mini-muffin tins and make 'tea cakes' with your favorite
recipe, substituting for the flour and adding xanthan gum w/ 1 tsp per cup
of GF flour.  I find that almost any recipe will do if baked in the
mini-muffin tins. Or, if you're set on a layer cake, make three layers
instead of two in a 9" pan so it won't be soggy in the middle
-http://www.nytimes.com/2005/02/02/dining/022nrex.html
-chocolate dipped strawberries or just strawberries and whipped cream
flourless chocolate cake (or any gluten free chocolate cake) - can serve
with whipped cream
If you have a Whole Foods nearby, you can get some almond scones and serve
them with jam
-GF Brownies cut in several shapes, GF cup cakes made in mini cupcake pans, cookies made in smaller sizes.
-How about Betty Hagman's choux pastry made into cream puffs or eclairs?  
You could have a Cream tea!  Yum.
A fruity quick bread with cream cheese. 
Angel food cake turned into petite fours.
-you can do choco fudge or peanut brittle
-Pamela's pancake and baking mix 
-You can make crunchy cookies with basmati rice ground as flour.
You could buy Whole Foods or another good bread and make 
party sandwiches: chicken salad, egg salad, shrimp, cheese, etc.
Don't now about pastries.  Edwards & Sons brown rice crisps are
nice, but get the ones made in Japan as they come from a gf 
factory (there is soy contamination tho).  The Canadian made ones
come from a wheat using facility
-Macaroons
Meringues
-Stuff a whole pitted date with an almond and wrap it in a length of raw GF bacon that is long enough to go around the date and secure with a toothpick.  Bake a pan of these goodies at around 300 - 350 or so degrees until the bacon is cooked.  (WATCH THEM!! It's easy to overdo them.)  Serve warm but not so hot that they burn fingers and tongue.  Mmmmm!
These are a little time consuming so it's best to prepare them ahead and bake just before serving.  Grassfed bacon is best of course because then the fat is actually good for you and you can lick those fingers with relish.  (www.westonaprice.org )
-"California Lemon Polenta cake" in the cookbook: Healthy Gluten-Free Cooking by Darina Allen and Rosemary Kearney.  Serve with fresh berries and sour cream (yes, sour, not whipped and it really is good).

* Please remember some posters may be WHEAT-FREE, but not GLUTEN-FREE *