I took a DLP projector (Casio XJ-A130) and hooked its HDMI input to a wireless Apple TV, and ran the audio to a Jambox. Very small footprint, setup takes about 5 minutes, and projected the image onto the hot tub cover. Excellent result. Whole setup could cost you around $350 for the projector, $85 for the Apple TV and $50 for a decent portable speaker. So for $500 you have access to iTunes movies, netflix, hulu, and a host of other video sources.
http://vimeo.com/81959780
