Actually, mine doesn't work out to exactly once a month. I figure there's no point in getting blood work done after just getting it done for the doc directly in his clinic, so I always recalculate my schedule for local monthly blood tests after every 3 month appointment.
I am like jbeany -- center is over an hour away, but get my regular labs at a local hospital 5 minutes away with standing orders there. My routine is very much like jbeany's. My labs get faxed to transplant center, local neph and GP. And then they are online so I can view them, too.