Regular readers know I love the HiRISE camera on the Mars Reconnaissance Orbiter. The camera takes fantastically high-res images of the Martian surface, and has done more to make Mars a real place in my mind than any spacecraft before it.
Regulars also know I love optical illusions as well as anaglyphs-- two-color images that look 3D when you wear the red/green glasses.
Put them all together, and you have the new HiRISE feature: Mars in awesome awesome awesome 3D. If you have the glasses (and you can find them online easily enough) you can look down into chasms, see mountains popping up at you, and almost feel the aeolian rippling of entrained sand dunes in channel floors.
This sort of thing is fun, but also provides a good scientific boost as well; you can actually get a sense of what you are seeing, instead of trying to interpret a flat projection. It might even help folks figure out the difference between a channel and a giant glass worm.