1) If you really stand a good chance, you will usually get a call within ONE WEEK after the interview. If after two weeks still no news, just safely assume its a no go and move on.

2) Just like nowadays "ONLY SHORTLISTED PEOPLE WILL GET NOTIFIED". If they never call you, just do not bother with any follow ups. You are not selected.

3) Apply for any position that you are interested even from within the same organization. It is really an open market right now. Do not wait because they will not wait for you.