Lord Ben said:
I have (actually I HAD them, they died now) a group of magic hating NPC's (Sentinals of the True Way in Kalamar) who tried to kill a few wizards. Anyways, part of the adventure was with some Rangers (no spells) who were sneaking up on the PC's. I gave them camoflage cloaks that added +4 circumstance to hide when in the woods. Perfectly balanced IMHO, wearing green in the woods should be a circumstance bonus of +2, finely crafted masterwork cloaks should add +4. Now the party has some camo cloaks at 4th level, not overpowering.
Very cool.

I might steal those...(just did).
+2 to spot would be a hard one. The best I can think of is goggles, and those don't feel fantasy to me.
Padded shirt, +2 to intimidate.
Tiger claws, +2 to climb, turns unarmed damage leathal.
Back pack, -2 to weight penalties due to even weight distribution.
Snowshoes/crampons, +2 to balance in appropriate situations.
Book on how to win friends and influence people, +2 to diplomacy.
Musical instuments, +2 to perform.
Wepon/sheath, +2 to conceal on your person.
Coin knife, +2 to pick pockets.
Compass, +2 (or more) to intuite direction.
I like this train of thought, especially for lower level play, or low magic worlds.