I've used v-trips in 1-1 laptop situations, in rooms with mobile labs, in laptops, and in rooms where the only computer belongs to a teacher. Ideally, you're able to connect the teacher's computer to a projector and arrange the classroom so you feel like a tour group.
One of the best v-trips I've seen was over 5 years ago when a French teacher with whom I'd worked closely found a fieldtrip CD at a language conference in Quebec. The CD was quite a simulation. It began with flight attendants taking your ticket, had participants on the plane, at an airport in France, and touring France to experience the language. The teacher arranged her classroom like an airplane, gave kids boarding passes, and served bread and cheese on the flight. In other words, she did her best to immerse students in the experience. Again, she did this with one computer, one projector, and one heck of an imagination.
One text resource which may be helpful, albeit a bit dated, is: V-trip travel guide: Classroom strategies for virtual field trips by Bob Kawka .