You could try to make a very simple solar cell. Find a metal with a very low work functin, shape it into a parabola, shine a light onto it, and put something to pick up the ejected electrons at the focus and use it to make a christmas light shine or something. Of course this makes an assumption I'm not sure I'm totally justified in making. I know that if you were to shine light in a parabola it would reflect and go to the focus, however I don't know that I can assume the ejected electrons would travel with the same trajectory? Also I don't know what you could use to collect the emitted electrons and put them through a wire. Perhpas someone smarter could help.