Projector screens can be pretty expensive, depending on the size and quality you're looking for. If you're thinking of installing one and want to save some money, you can build a pretty decent one yourself with just a few simple materials. Redditor dodgeboy made this 128" DIY projector screen for only $200, and I have to say it looks pretty impressive.
Poplar 1x4s make up the frame, with pine 1x3s as supports.
Once the frame was assembled and painted black, he installed mounting blocks on both sides to hold it in place and compensate for any gaps between the frame and wall.
Next, he stretched spandex over the frame, trimmed off the excess, and put on a felt border.
After mounting, here's the final product:
I, for one, would never guess that this was homemade! If you'd like to build one of your own, check out dodgeboy's step-by-step guide for more details.
Already have a projector screen? Try hacking an old-school overhead projector into a digital video projector or using your iPhone as a projector. If you don't have a screen, you can also use Screen Goo to turn almost any smooth surface into a screen.