Mykal, the key is to request cities where there is a default connection on your airline of choice. In this case, if you can pick 4 cities, request BWI to STL to SDF to STL to BWI. The options for each portion will automatically include a connection through a hub, DTW, MEM, or maybe CLE or EWR. Choose a flight, continue to book, and the fare shold work out.
If you guys are REALLY TRULY looking for the most segments on this type of itinerary, the same BWI-SDF fare allows travel from BWI-
EWR-DTW (or CLE)-STL-MEM-SDF-MEM-STL-DTW (or CLE) -
EWR-BWI. Mykal, wouldn't it be unfortunate

if you missed your last EWR--BWI flight??
FWIW, I don't think you can complete the round trip via EWR in one day.
[This message has been edited by Viajero Joven (edited 08-15-2002).]