What is the best way to follow up on this job interview?

I am looking for teaching positions for the fall – so districts have plenty of time to full their open positions. About two and a half months ago I had an interview with the largest school district in the area. The interview went well and I was told I would get a call soon to visit school buildings and interview with principals for a placement. I didn’t hear back for about three weeks, when the gentleman I interviewed with called to say that he is still planning to send me to buildings and the interviews should be scheduled within the next two weeks. It has now been three and a half weeks and still no word. I had an interview with another district yesterday (not my first choice), they said they will be making a decision within the week, and I think I have a decent shot.

I want to follow up with the interviewer at the first district prior to accepting any offers but I am not sure how or exactly what to say. Would it be more appropriate to call or send an email? Should I say I am considering another position? Do I just come right out and ask if I am still in the running?

Any advice would be appreciated!