TM is right.  Unlike you, I am much older, but am also playing the waiting game.  Don't alienate anyone with frequent phone calls.  They have many other responsibilities; hiring decisions are not their priority.  I know, it is your greatest concern, but they are not in your shoes.  Timetables vary; most employers with whom I have interviewed never make decisions during the timeframe they initially give me.  For example, I applied for a position last May, (2006); they contacted me for an interview in late July.  I met with them the first week of August.  It took them 3 months just to begin the interview process.  I waited a few weeks before following up; no response.  I waited a few more, then emailed to inquire about the status.  When I received a response, the director advise me that she had not contacted me sooner because they had a 2nd position that they were filling from the same applicant pool.  I was not hired. 

More recently, I had 4 interviews, all about 2 months ago.  It took one employer around a month before making a decision--that was relatively fast; (I didn't get the job) another employer took 6 weeks before contacting me; again, I was not hired.  Of the 2 that are still pending, one has not returned any of my telephone calls, I have essentially written them off because if they won't extend the courtesy of a call or email in response to my courteous, infrequent inquiries, they probably don't have their act together.  A week ago (last Friday) I spoke with the director for "job 4" who told me that she is still working on it.  She has been working on a reorganization in another department that has consumed her time.  I told her that I would love the opportunity to come to work and help her with it!

I try to wait about 2 weeks before following up.  Then I wait another couple of weeks, depending on what I learned about the status previously, if I actually spoke with someone.  You shouldn't expect a return phone call within a certain timeframe.  The person you called could be out of the office ill, attending a conference, in training, on vacation, dealing with a personal emergency or unanticipated problems at work.

It is time consuming and very stressful for those of us waiting to move forward with our lives.  Don't give up so soon, and be careful about how often you contact them and what you say.  The smallest thing could end up costing you the job.