Additional cabin handbag on flights
On many airlines (at least in the US), you are often allowed one "personal item" in addition to your carry-on bag. For example, Continental Airlines says:
In addition to the one carry-on item, you may bring one personal item such as a large shoulder bag, large backpack, laptop bag or an item of similar size.
The guidelines for the regular carry-on bag and checked luggage are very specific (weight, size in linear inches, etc.), but the "personal item" description always seemed fairly vague.
Practically, what can count as a personal item, and what would be turned away for being too large? If an item was rejected for not meeting the policy, when would it be rejected, and what would happen to it?