I have been searching ways (with spells and items) to enhance the spot check and ways to enhance the hide check (with spells and items). We have a PC in our campaign maxing out his spot and another maxing out his hide, we noticed that the first player is unlikely to spot the other hiding.
For Hiding an easy combination found is to get a high bonus of +15 (greater shadow), that could stack with the spell camouflage +10 (Spell Compendium 43).
Also it is enough to become invisible and automatically get +20 or +40 bonus to hide checks as written in PH, this can be countered by spells like true seeing, but these have a limited range (in this case 120 ft.).
The same cannot be said for spot checks, the best I have found from manuals is a +10 robes of the eyes (DMG 265), which is very expensive in comparison to the greater shadow bonus mentioned above. some items that give low bonuses like +1 (luck) or +2 (alchemical) could be added.
I wonder if I am missing something or the spot enhancements were thought to be inferior to hide.
Also, as a DM, what would be the implication of creating an item that gives +15 spot - so an equal bonus to greater shadow?