Should I let potential employers know I have a job offer? I've interviewed for a few positions, one of which has made me an offer.  I'm very pleased with the offer, but I prefer some of the other positions.  I have the luxury of being able to take a lot of time to decide whether or not I accept this offer, so I'm certain I will hear back (either positively or negatively) from the other positions before a decision is required for the offer I've received.

I'm trying to decide between two courses of action, and I want to choose the one that will best help my candidacy with the positions I've yet to hear from.  Plan 1 is to do nothing and simply wait to hear back from the other positions for which I've already interviewed.  Plan 2 is to be in touch with the other positions to let them know I have an offer, and ask where I stand with them.

Would Plan 2 make me a more desirable candidate with the other positions, as they might see my offer as further validation of my credentials?  Or, might initiating with the interviewers in this way be detrimental to my candidacy, perhaps making me seem pushy or self-centered?  If so, I would rather just wait for them to run their course of action (Plan 1).  As I've said, I have plenty of time, so I don't want impatience to hurt me.

If there is a good chance that my meddling will be detrimental, then I'd rather be hands-off here.  However, if it's more likely that informing the other interviewers of my offer will give me a boost, then I'd want to do so.

Thanks for any clarity you can provide!

Edit: For a bit more information and context, the position I've been offered is a non-academic research position that my advisor has described as "prestigious."  The other positions for which I've interviewed (and which I prefer) are mostly academic teaching-centered positions (visiting assistant professors, tenure-track at smaller four year institutions).
The argument for plan 2 is that if you have an offer from employer A with a particular deadline but you would prefer to take a position with employer B, then if you don't say something, employer B could take too long to decide what to do and you'd be forced to take offer A before employer B gets around to making you an offer.  

I've been on the employer side of this (as both employer A and employer B.)  Keep in mind that once a search committee has completed interviews it has to meet to decide on who should be offered the position and then this has to be reviewed by higher level administrators (deans or vice presidents) and that the process can take time (days or weeks.)  It may be possible to expedite this process if there's a particular deadline, or it may not.    

I think that if you've decided that you'll take offer A by a particular deadline if you have no other offers (and that you wouldn't break your contract with employer A after accepting the offer), then you should tell the other potential employers about the offer and the deadline (I wouldn't mention employer A's name or the specific amount of the offer.) It's not likely to hurt your chances with these other employers, but it could help motivate them to get an offer out to you in a timely fashion.

I have received this kind of information from job candidates in the past.  Unfortunately, I've always had to say that (because we had other candidates scheduled for on campus interviews) that we couldn't make an offer before the deadline.