We just returned from Saint Thomas(USVI), the main reason I chose this as a vacation spot was my understanding that no passport etc.. will be required, to my surprise everyone returning was required to show a passport and go through custom and immigration just like returning from Canada or Mexico. Fortunately we had the GC's and the children's birth cert., and a kind IO who was willing o listen and spend a few extra minutes and allowed us back into the US, also while boarding from San Juan, Puerto Rico, we were once again asked about immigration status and proof...so to the Gurus, would you list travel to USVI and Puerto Rico as travel outside US for the N400 purpose.