We did the open jaw A-B and then B-C two or three years ago. We flew from ROC to LON(via Philadelphia ) on BA (and USAir code share), then from LHR - PIT . We then used FF award tickets to on USAir from PIT to SEA, and finishing up a week later flying SEA - PIT-ROC. Yes, I knw we could have done LON to SEA, but had first class freebee's for the PIT-SEA and return segments.