Baby food rotation happens automatically when the bottles are stored in alphabetical order
Mike's tip for making sure his baby gets something different to eat at each meal:
We've started feeding our five month-old baby solid food. We have six varieties of Stage 1 food (Earth's Best) and after trying them to ensure he had no reaction, we thought of how to make sure he gets a different flavor every day. It occured to us to simply give the foods in alphabetical order (Apples, Bananas, Carrots, Peas, Pears, Sweet Potatoes). This is also a great game for his 5 year-old brother, who helps us select the next food (and is quite good at remembering what his baby brother had the day before--perhaps better than his parents.)
For the more visually oriented: make sure you mix the colors together -- variety will happen naturally.