Depends leh, knowing someone in HR probably wont help at all. I had a friend who technically pulled string. He was a medic with me at one of the medical centres, closer to ORD, he asked our DXO supervisor if he can sign on. Of course, supervisor say okay, more help at the medical centre means less work for him. Although the position was only for degree holders, my supervisor managed to get him an interview and he got the job. Of course, my friend is an extremely reliable person. He only had a diploma so they sent him for part-time degree as well.

So it depends who you know. I think if you know someone within the department or unit you want to head to, its possible. But if you only know the HR person, it wont work.