Today the Federal Circuit held en banc that a statutory ban on end-running U.S. patent law doesn't apply to "method" patents.
Congress passed the ban, which you'll find at 35 U.S.C. 271(f), in 1984. It aimed to void Deepsouth Packing Co. v. Laitram Corp., 406 U.S. 518 (1972), in which the Court held that the export of machine pieces for assembly overseas didn't count as patent infringement. Section 271(f) counters Deepsouth by saying that you can't avoid infringement by completing domestic work in foreign climes.
The full court ruled (with a lone dissenter) that the ban doesn't reach "method" or "process" patents, which claim a series of steps that produce results instead of a thing that results from those steps. Cardiac Pacemakers, Inc. v. St. Jude Medical, Inc., No. 07-1296 (Fed. Cir. Aug. 19, 2009) (en banc). Taking a step in the U.S. and another in Kazakhstan (say) to make a widget thus won't get you into section 271(f) trouble if you infringe a patent that claims a method for widget-making but will endanger you if you infringe a patent that claims the widget itself.