I've been to Port Moresby. Are you going for business, cultural trip or dive trip? The capital has an earned reputation for potential violent acts by "rascals". As I go there on my way to dive locations, I try to spend as little time there as possible, however when I have to overnight or have a long layover at the airport, I go to Loloata Dive Resort on Loloata Island. Very nice guy runs it and they come to the airport to pick you up.