Have lap-tops at each desk as the students walk in along with the assignment sheet. Have the students sit with their groups.
Explain that they are going to be working on their presentations based on the metaphor/concept they came up with. If they need to meet up and remind everyone of that concept encourage that. See assignment sheet for details. Your presentation will look like the example one given in class. Work individually and work as a group to prepare your presentation. Monitor how far along everyone is getting on their presentation to determine if you need another day or if you can go ahead and start presentations next week.