Nearly everyone in Honduras uses both Honduran lempiras and U.S. dollars. You can literally pay the hotel in dollars, they will figure out the exchange rate for lempiras, and give you change in lempiras. Check the exchange rate beforehand - we found that some places gave us 17 lmps for $1US, and others gave us 18 lmps. We didn't exchange money once at a banking institution during our entire 2 weeks in Honduras.
Sun Jam is a HUGE party that is organized by the local dive shops on Utila. It is held in August every year on Water Cay. It is a lot of fun if you are young and in that "partying mode," however for us "old folks," it became an annoyance. Hotel prices went up, hotel rooms were few and far between, and many of the dive shops closed completely for the entire weekend.