Like champion surfers, large international design firms are riding the crest of a wave for all it is worth. Markets are strong and varied, as are the geographic demands for design services. There are some warning signs of a slowdown as the same high oil prices that have fueled market booms in oil-producing regions threaten to slow frenzied markets in the other areas of the developing world. Also, the banking crisis has made it harder to obtain development capital. But like any experienced surfer, design firms are maneuvering to make the ride last as long as possible.