I always make it a point to purposely step on every Aroma Trap I see. My team can easily handle the attracted Pokémon and get some free experience in the process. Plus, it is a nice way to run into recruitable Pokémon during one's first trip to a dungeon.
In Lv. 1 dungeons, Warp Traps can also be useful provided that you entered alone and haven't yet recruited anyone. It could warp you closer to the stairs or away from a particularly irritating wild Pokémon.
Also, on a floor with a rare Pokémon (such as Chansey), you can use Pokémon Traps to your advantage. If you bring 99 of a throwing item and scatter them all about the floor, you can step on a Pokémon Trap to replace them all with wild Pokémon. A few of those 99 will probably be the rare Pokémon in question. However, because this essentially creates the world's largest Monster House, you should be powerful enough to fend off about 99 foes in succession. You can also do this in a dungeon with Pokémon that yield a lot of experience to level up quite quickly.