Yeah, I hate doing the paladin detect-o-meter as well. It's too bloody useful, though - but to be honest, unless the target is stupidly high level, an evil cleric, or an evil outsider or undead, almost everyone you encounter will register as 'faint evil' at the most. 'Faint evil' isn't something I consider enough evidence to play whack-a-mole, since it could be the residue from bumping into an evil creature.
I mean seriously, think about it: the bartender who steals from his customers radiates the same amount of evil as a CE Ftr 9 who slaughters villages for breakfast. It's not exactly an exact power.