Beerbelly didn't have any the last few times I checked (not a big enough market for it IIRC) and I've checked a few health stores with no luck. Funny side story at one though;
I went into one store, looked through what they did have and noticed they were all using the fancy names to make people think they were something other than simple products, so I figured I'd ask for exactly what I was looking for...
Me: Do you stock flaked maize?
StoreGirl: Let's have a look [at the shelves I've been staring at already, because I didn't think to look there]... nope, doesn't look like we have that. What is it again?
Me: Flaked maize...
StoreGirl: What's that exactly?
Me: You know, corn... flaked corn.
StoreGirl: I don't think I've ever even heard of that before
Me: Um... Flaked Corn, as in Corn Flakes...
StoreGirl: Oh. Right. No, we don't have those.
If you do find somewhere that stocks it please let us all know, otherwise I reckon I'm sticking with the polenta.