Do I need to bring a passport to travel to the U.S. Virgin Islands or is a photo ID good enough?

Your DL or State ID is enough. The US Virgin Islands are a US territory, so counts as a domestic flight, like any state. This is from the DHS web site: (this apply to permanent residents too) Traveling to and from U.S. Territories. U.S. Citizens traveling to and returning directly from a U.S. territory are not considered to have left the U.S. territory and do not need to present a passport. U.S. territories include American Samoa, Guam, Northern Mariana Islands, Puerto Rico, Swains Island and U.S. Virgin Islands.  more