What will the overhead projector look like 10 years from now?

Theres a good chance that the O.H.P will be obsolete in another 10 years. You can already buy U.S.B projectors to plug into computers and with the cost of such technology always going down, more and more organisations are converting. Presentations can be made quickly and easily on a computer and can include all manner of detail such as photographs, animation and video. Some laptops are even small enough to put in your pocket. With this kind of affordable versatility it is unlikely that the overhead projector will remain viable or practical in most situations for much longer. As long as there are replacement parts readily available, however, existing O.H.Ps will undoubtedly remain, especially in schools for some time. As for what new ones will look like should they still be in production 10 years from now; I imagine they will look about the same, give or take a slightly different asthetic design... maybe they will be silver instead of grey, or maybe they will be made from a different material. The basic design principals, however cannot be improved upon a great deal, and hence you will always be able to recognise an O.H.P for what it is.