The company Bright Horizons specializes in providing back-up childcare. Generally they contract with employers to provide such care in fully accredited centers- close to major employers
When traveling to ATL last year, I inquired with the local center to see if they would take my daughter (even though my employer only offers the service in my home state). They agreed to do so at a very reasonable daily rate. I was pleased with the center and care.
I did have to fill out a ton of paperwork- the are accredited, so it is like starting at any other daycare center in the states.
My daughter enjoyed her time at the center.