Has anyone thought about Greyhound or the other major bus lines? They might have regularly scheduled runs between Washington, D.C., and Annapolis. As for taking a cab between the two, it would probably be much less expensive to rent a car for the day. Most of the major car rental agencies have offices in downtown DC and it's actually cheaper to rent in the city than at the airport because they tack on extra airport charges that aren't included when you rent at non-airport locations. If you know what day you're going to want the car, you might check the on-line web sites of various rental agencies and reserve on line - you get some good deals. As for transportation within Washington, DC, with the zone fares that taxicabs charge, cab fare can become rather expensive. My daughter rides the Metro (subway) every weekday with no safety problems. There's a branch of a large motel chain near the Maryland end and my daughter rides (and chats) with a lot of tourists who are very happy getting around on the subway. Like any city, it's what part of the city you visit. For anyone visiting Washington, DC, Metro has a web site that allows you to plan your subway trips, shows timetables, etc. You have to scroll to the right when the homepage appears to see a list of their options. Here's the web site: http://www.wmata.com/ Barbara