Just finished a clinical at Children's and the nurse recruiter gave us tips on how to get hired there, especially NICU (most competitive area):
-previous tech/student nurse experience, preferably in a children's area AND/OR volunteering in a NICU
-shadowing experience in the NICU (or whatever area you desire there)
Most important I think was that the applicant showed a genuine interest in NICU through some kind of prior experience
She also mentioned "well roundedness" and good academics were also additional criteria. She also said the same thing about there being 150 applicants for NICU.
(I am not interested in peds, or else I think I might not be willing to share this with others