Put me to sleep, evil angel...
Actually pestering doesn't really work. In most cases it just annoys them and gets them to decide NOT to hire you. If you haven't heard back within a month call and check on it once, a second time two weeks after that, but no more than that.
It should go without saying that you should be nice and polite and not be overly confident when talking about applying, or turning the app in. Be confident, but not overly so. But you'd be surprised how many people come in to ask about a job or turn in an app at my work and are totally rude or act like their too good for the job. Idiots.
RESUMES ROCK!
If you get a call-back and can't answer, or they leave a message for you (sometimes they don't, but it should still be on the call ID) you have to call them back. They will not call twice.
...Open your wings, evil angel