Slowdance

This is a device vibrates the objects placed within the frame at one frequency and strobes light on the objects at a slightly offset frequency. The difference between the frequencies called the beat frequency creates an optical illusion ghosting affect.
The creator of "BCrypt", a common library for cryptography for web apps (in fact, the password you use for this site is secured with bcrypt), "Yan" made one for a weekend project and posted about it on TwitterーWhich is how I found out about it. But, you can hack an IKEA frame to do it yourself using this Instructable.