I am applying for junior faculty positions this fall. I know professors at several of the institutions where I'll be applying, but not in the same department to which I will be applying. Are letters from people at the same institution where I'm applying more valuable than an equivalent letter from someone at another institution?
Also, what if I do know someone in the department where I'll be applying. Should I rely on their input into the search process occurring naturally during faculty discussion, or would an explicit letter of recommendation from that person be looked upon favorably or disfavorably?