Floating Holographic Heads & other Decorations

By buying a DVD called Big Scream TV, you can turn your TV into an impressive Haunted House or Halloween prop. Spending a little extra on props to embellish the effect makes it look even more impressive, but based on the cost of the DVD's themselves (about $10, depending on where you buy them ... see here for a link to eBay auctions for them) it is a very inexpensive way to create a dramatic look.

Links - Big Scream TV Official Site (includes a tips, examples of how it works, and a forum for users of the DVD) / other props and decorations