I just wanted to get your thoughts on the types of clever traps that a PC could build for use during a campaign. I've done some reading on other sites as well as tried to come up with my own. One thing that I want to get your opinions on is how "fair" the traps are. It seems as though the intent of the authors when developing rules for craft - trapmaking is that the traps are used in a dungeon, castle, fortress, etc.. setting. The way that I've read it is that's the reasoning behind being able to have automatic reset traps that cost more time and money to craft. Also, magic traps factor in the cost of the spell materials makes me think that there needs to be a bowl of the materials there for the trap to "cast" the spell over and over again. With that being said, I think it's fair for a PC to have portable traps so long as the DM agrees to it.
When I discussed it with my own DM, I described the traps being similar in nature to a military claymore mine. The simplest example I could think of is a low level burning hands magic trap. The PC can set up the traps relatively quickly (1 standard action per trap) while the other PCs plan an ambush. The trigger can be either mechanical or spell triggered (based on how it was crafted). Once the ambush is sprung, the trap(s) go off and the battle is won, the trapper PC can gather the traps to be used in a future battle.
Here are some other "traps" that I've read about / thought of:
Remote "Bomb" - Similar to the claymore mine type trap above but with a remote trigger that can be activated by a PC rather than a mechanical or magical trigger. Perhaps it's something as simple as having the trap activated by a command word and having the PC communicate that word to the trap somehow.
Healing Trap - I've read several examples of this one and it really seems to get abused. One was having a simple needle trap installed onto a breastplate. The needle trap was set up to automatically reset and cast cure light wounds. Every time the PC was hit in combat, the needle trap would go off. The needle would do minimal damage and cure light wounds would go off, healing the PC. Another healing trap I read about was basically a small chamber in a castle. When a PC would enter the chamber, the trap would detect good as a trigger. If it detected good, the trap would activate and cast cure light wounds.
Does this go against the spirit of what trap crafting is all about? Should the trap crafting PC be able craft portable traps? Should "traps" be able to heal? I suppose if you look at it from the perspective of using the "Craft Wondrous Item" feat to create magical traps, I can see how a PC could create a magical device to heal. Maybe I'm just getting hung up on the word "trap".