I have always been enamored by 3D, from red/green anaglyph glasses viewing comics, to lenticular prints of boats (Canal ST, NY had a huge array of lenticular images on display - they are easier to make than the used to be)
But the truly autostereoscopic (3D spatial viewing without special eyewear) of digital images is still a promise in the making. Here are two new examples of commerically availabel devices which promise a real time 3D "Holographic" experiance.
This will improve, but right now, they lack definition. For example this early version LookingGlass consumer level display has a resolution of around 768 x 576 (remember that). Here is a quick and dirty 3D render of the Catholic Church, next to the John Lennon Building.