The Paizo/Pathfinder Spell "Trap the Soul", has two possible triggers.
Spell Completion: First, the spell can be completed by speaking its final word as a standard action as if you were casting a regular spell at the subject. This allows spell resistance (if any) and a Will save to avoid the effect. If the creature's name is spoken as well, any spell resistance is ignored and the save DC increases by 2. If the save or spell resistance is successful, the gem shatters.
The Second is:
Trigger Object: The second method is far more insidious, for it tricks the subject into accepting a trigger object inscribed with the final spell word, automatically placing the creature's soul in the trap. To use this method, both the creature's name and the trigger word must be inscribed on the trigger object when the gem is enspelled. A sympathy spell can also be placed on the trigger object. As soon as the subject picks up or accepts the trigger object, its life force is automatically transferred to the gem without the benefit of spell resistance or a save.
This second one is important. To read the RAW, (Material Cost Aside) as above, without the benefit of a save or spell resistance it seems to me that a sufficiently prepared spellcaster with the Soul Trap spell and some crafting time (for the enscription) would be able to use these as a kind of ... poke ball? Knowing the creatures name and inscribing both the name and the trigger word means that as soon as the creature touches the gem they become trapped. Would this allow for a ranged-touch attack to throw the gem at them and trap them?