Self-Administration of Allergy Medication for Children

Allergizer recently posed a provocative and important question for parents of allergic children: at what age can children with allergies be responsible for administering their own allergy medications? There's a lot of "there" there --- responsible management of medication includes not only recognizing symptoms and being prepared to administer medication properly, but also keeping track of where their medication is and letting adults know about side effects and any unusual effects of maintenance medications like antihistamines or daily asthma medications.

Personally, I remember being responsible for my own fast-acting asthma inhaler around the age of seven or eight, but speaking as a parent it seems difficult to decide when individual children are ready. Parents: how have you made the decision? What are some good baselines for other skills that can help indicate that your children are ready?