My suggestion would be to build contacts because you want to, not because you feel you have to. Here's what you gotta do:
1) Find a doctor who does something you're very interested in. Don't worry if they're on the admissions committee, just be sure your interest is genuine.
2) Contact them, preferably via e-mail, and tell them that you're very interested in what they're doing, and could they tell you some more about their work? Mention that you're applying to the school. If you're local, it may even be possible to arrange a meeting or shadowing day with this doctor.
3) When secondary/interview time rolls around, you will be able to mention that you have been in contact with this doctor. Not only will this signify that you have a interest in this school, but it also shows that your interest in medicine is genuine. Trust me, even if the doctor you contact isn't on the adcom, the doctors will surely know each other.
I would advise against harassing admissions committees unnecessarily. It's absolutely fine to request informational materials from them or check your status, and it's nice if they know who you are later in the process (ie, when interview time rolls around). But if they know your name at this juncture, it's usually because you've been an unrelenting pain in the ass. Think of them as more of a resource than a contact right now. Contacts should be people you pick out because you're genuinely interested in what they're doing, not because you think they'll increase your odds of acceptance. Besides, anyone affiliated with a med school has a sixth sense for premeds who brownnose, and no one appreciates that. If you're sincere and interested and polite, however, that could get you very far.