Glogster
Free to register. This site allows students to make online multimedia posters, called GLOGS. GLOGS can contain text, photos, videos, graphics, sounds, drawings, data attachments and more. This is a particularly good resource for students who have difficulty with physically making a poster (cutting, pasting, and planning a layout), but it can help all student to put together really impressive presentations.
ReadWriteThink
This is a resource for learning how to design posters for class presentations.
Screen Tek
This page provides resources to help students improve oral presentation/ public speaking skills. It was recommended to us by a student who found it useful (we always appreciate suggestions).