How do I get Nooks and Crannies in my English muffins?
I found a great recipe for English muffins, which is a variation on Alton Brown's recipe.  Basically, the variation calls for adding a bit of baking soda after proofing the dough.

I've made this recipe a couple of times, with very satisfying results.  The yeast flavor is a bit strong for those used to store-bought, but I like it.