[Aliantha]

You merkins are weird. We just use self raising or plain flour for baking here too (like in the UK).

You could just as easily add corn starch to the flour if that's what you wanted for your cake flour. Some sponge cake recipies call for corn starch, and the reason is pretty much what Bruce's article suggest. It gives the cake a different texture. Personally I don't particularly like those particular recipies, but some people do.

eta: packet cakes are moderately popular over here, but most people these days seem to buy cakes pre made if they're not going to make them from scratch. Maybe I'm naive about how many people use packet mixes though. I really feel like it's a cheat, but then, I was lucky to be raised by a woman who had 'baking day' every Monday and we'd come home from school to house with at least one nice fresh cake, and the cookie jar topped up. (My Mum would flip in her cannister of ashes if she saw me using a packet mix)