Ready an Action: valid conditions

[enrious]

But remaining still IS still doing something. Also, the Halfling is breathing, that would qualify as "doing anything". Also, I am sure the Halfling is in some way defending himself or taking a defensive posture (not just standing still like a statue). That also qualifies as "doing anything".

Might as well use the Readied Action:

I ready an action to take my turn should anything occur during the round which I would like to react to.

"Readying an Action: You can ready a standard action, a move action, a swift action, or a free action. To do so, specify the action you will take and the conditions under which you will take it. Then, anytime before your next action, you may take the readied action in response to that condition. The action occurs just before the action that triggers it. If the triggered action is part of another character's activities, you interrupt the other character. Assuming he is still capable of doing so, he continues his actions once you complete your readied action. Your initiative result changes. For the rest of the encounter, your initiative result is the count on which you took the readied action, and you act immediately ahead of the character whose action triggered your readied action."

A refresher course in Pathfinder may be in order as breathing is not defined as an "action", to say nothing of the fact that you must specify the action you will take.

In any event, also one thing to remember is that if a readied action is triggered, your initiative permanently changes for the rest of the fight (well, unless you do something else to change it, such as Delaying or going unconscious).