For Trapfinding, the Lists of Stuff says:

Trapfinding
Barbarian 3, class variant, Dungeonscape, replaces Trap Sense, see text
Rogue 1
Ranger 1, class variant, Dungeonscape, replaces Track
Beguiler 1, Player's Handbook 2
Ninja 1, Complete Adventurer
Scout 1, Complete Adventurer
Spellthief 1, Complete Adventurer
Nightsong Infiltrator 1, ecl 8, Complete Adventurer
Geometer 3, ecl 9, Complete Arcane, Traps based on writing only
Temple Raider of Olidammara 1, ecl 6, Complete Divine
Stoneblessed(Dwarf) 3, ecl 5, Races of Stone, stone traps only
Stonedeath Assassin 1, ecl 6, Races of Stone
Artificer 1, Eberron Campaign Setting, disable traps
Silverkey 1, ecl 4, Eberron: Dragonmarked, called "wardsense", works at range, see text
Factotum 1, Dungeonscape
Disciple of Dispater 2, ecl 8, Book of Vile Darkness, metal only
Kobold domain, Races of the Dragon, web enhancement
Theft Gloves, soulmeld, Magic of Incarnum
Hoardstealer 1, ecl 6, Draconomicon

special mention
Planar Touchstone (Catalogues of Enlightenment), feat, Planar Handbook, gain the ability of a chosen doman (pick Kobold, see above)
Trap Sensitivity, feat, Dungeonscape, do not have to search for traps actively, see text