the beautiful innards of video projectors
Optical components are precious and expensive, and unwanted LCD video projectors provide an especially rich trove of beautiful and exotic optics. I've found that any given LCD projector will yield the following:
-Projection lens assembly (of course)
-Positive and negative lenslet arrays, typically AR coated (this forms the first stage of the lamp condenser)
-Several first surface metal-substrate mirrors
-Several PCX lenses (illumination relay feeding the LCDs)
-Three small LCD screens, if you can make use of them
-Several dichroic filters
-And the pee-ess de resistance: A three-way cross-cube dichroic beamsplitter... wow. Folks have caught on to how beautiful these are (aesthetically, not the way maths are beautiful). These can be found on ebay being sold as decorative items.
All of these tend to be of relatively high quality and typically AR coated. In addition you'll find a great source of cooling fans, with at least five per projector.
Therefore, to throw one in the garbage would be simply tragic.
For more on optical recycling see the Camera Light.