I second this, plus the Pho 75 comment for the Washington DC area (they are everywhere, but the Eden Center location near Seven Corners has to work for it). Now that I live in Boston, many people say that Pho Pasteur is good, but for my money, I recommend the drive out to Pho Lynn in Lynn, MA.

There's also a thread I started on this topic about Pho in Paris, another enclave of fantastic Vietnamese food:

http://www.flyertalk.com/forum/showthread.php?t=460062

Timothy

Of course, UA flies one-hop direct to SGN now. You can get the real stuff right off a real carrier.