Liquid crystal display projectors are easier to use for class presentations since they have direct links to computers and can project a PowerPoint presentation onto a wall. But, overhead projectors work the same way, they just need transparencies. Transparencies are inexpensive and any standard photocopier can copy onto them. To lower the number of transparencies needed for your classroom presentations, pair up the students or have them work in larger groups. Science and business topics work especially well for an overhead projector project since the students can project scientific explanations or business graphs easily through the transparencies.
One of the most difficult hurdles for a writing teacher to cross is how to get the students involved in the editing process -- to become better writers they need to become better editors. An overhead projector is an effective tool for group editing practice. Prepare an editing form beforehand organized into specific sections for organization, grammar and content, and give it to the students. Get the permission of two or three students to use their writing as an example. Create transparencies from those examples, project them onto a wall or whiteboard and work as a class on the specific examples.
Overhead projectors are useful art tools for students of any age. Kindergarten children can learn to color within the lines and trace objects onto a piece of paper or whiteboard. Choose a particular picture to use, create the transparency and project it. Then have individual children or groups color in the photos. Hang them on the wall when you're finished. This is a good project for any level of artists. To create an outdoor wall mural just take the projector outside and project any image onto a wall, have the students trace the main lines and then color in the rest of the mural.
A single overhead projector is not large or strong enough to do lighting for an actual stage performance, but will work to project light onto the front of a classroom for smaller performances. Have your students create advertisements they can act out in front of their peers. Use the overhead projector to change the background colors for the ads. All you need is standard stage lighting gels or colored plastic sheets. Have the students experiment with the different colors to come up with imaginative backgrounds for their performances.