There's the level 1 "Instant Search" spell from Spell Compendium for Assassin, Ranger, Wiz/Sor. The spell is swift action to cast, personal, 1 round duration, and during the round, you get to make one search check with +2 insight check. If you persist the spell somehow (Chemeleon -> DMM, for example), and if your DM is kind enough to interpret the "You can make one Search check in this round as a free action." as "You get to make one every round during the duration."...
-K