I wholeheartedly agree that the grain-based cereals (hot and cold) are great for our birds!
I would just like to add that neither sugar nor milk are toxic. TINY amounts of each are no more problem for them than they are for most of us.
IMO, it is a myth that birds are lactose intolerant and that milk gives them diarrhea. All the supposed cases I have seen turned out to just be extra urine from drinking more liquid (the milk).
Remember, true diarrhea in a bird results in a completely homogenous dropping - no separation between urine and feces. A bird with extra urine will have a large wet dropping, but there will be at least some solid feces in it.
Keep in mind that moderation is the key here. I do not recommend feeding any of the "sugar frosted" brands, but if you have sprinkled a tiny amount on your bowl of cereal that includes milk, it is ok to give your bird a spoonful.
I think there is a lot of unnecessary paranoia amonst people who don't understand or practice moderation and common sense when measuring proportions when it comes to these foods.
Having said that, I also agree that soy milk is healthier because it provides some valuable protein and other micronutrients.
Dr. Mike (who hopes this post won't be considered too politically incorrect)