Spiderscribe is an easy-to-use mindmapping application that allows you to upload pictures and documents to enhance your "web". From the site: "It lets you organize your ideas by connecting notes, files, calendar events, etc. in free-form maps. You can collaborate and share those maps online!" Maps can be private or public, and can be a way to marshall resources needed for a presentation. Students simply login to their account and all their material is in one place.