Planning a trip? Need a passport? If you attend the Boston Globe Travel Show at the Seaport World Trade Center on Friday, Saturday, or Sunday, February 19-21, you’re in luck. The United States Postal Service will be accepting applications at the show and there will be a photo service available for you to have passport photos taken. The Boston Passport Agency will also be present at the Show to help answer any additional questions you may have. If you don’t apply for a passport at the show, you can apply in person at one of the 9,000 accepted passport facilities around the country (many post offices can process passport documents). To find an office near you, go to www.travel.state.gov, and a link from there will allow you to enter your zip code for a list of locations in your area. Either way, you’ll have to fill out an application (form DS-11), which will be available at the show, and provide several supporting documents (see sidebar). Each passport costs $100 and takes four to six