The mimics reminded me of the traps in Sen's Fortress, and the floor switches that activate arrow traps that can be used to your advantage to kill bad guys. That also which got me thinking of other, similar traps. Traps that don't activate when you touch them, but give a warning click or something, and then activate when you leave are interesting, since you get that "o shit" moment and then can plan a desperate, unlikely plan of escape to avoid damage.
Also, the boxes you find rarely in the 3d fallout games that have a grenade wired to the side, and explode if you open the box without noticing and taking the grenade first. It's a very simplistic version of the standard trapped chest idea from RPGs, but without needing any kind of game mechanic other than the player noticing and frobbing a thing.
edit: The STALKER example reminds me of the land mines that are in Call of Pripyat. You similar to the anomalies, you feel them out by throwing bolts, but instead of a big dramatic effect, you get a little *clink!* noise. On the other hand, if you step on one yourself, instead of getting sucked into something you might possibly escape... you just fucking die with a loud noise. Very stressful, and thankfully only in the one spot, but as a novel challenge it was cool.