What are good techniques for getting gluten free bread to rise? I make gluten free bread in a bread maker, however I can never get it to rise as much as 'regular' bread and is usually a little heavy. What techniques/recipes/substitutions can I try to get my gluten free bread to rise more?

I currently use a recipe that is similar to this one here, but with a bit of tapioca starch instead of buckwheat flour.
Baking soda comes to mind. Irish soda bread can be gluten-free, and uses baking soda for its rising action. The crumb is fairly loose though, did you want something that would hold together better?