I've seen stacks of dominoes, playing cards, some small iPods… even icons, right there in the Mac OS X 10.5 Leopard Dock. But a pile of Macs, even a huge one like that, and with so many classic machines … a huge novelty!
The owner of these beauties Nate Crank, who posted the photo exactly three years ago on his Flickr. From top to bottom, they are: Mac Plus, Mac SE / 30, Mac LC, Mac IIc, Performa 6200CD, Mac Centris 610, Power Mac G3, Power Mac 7200, Performa 6400/200, Power Mac 6500/250, Power Mac 8600/300 and PowerMac G5 Dual 2GHz.
Interestingly, of these only the most current, the G5, does not work. That's because Macs don't usually survive floods, according to him … And if you need any reference, amaze: the guy in the photo is 1.98m tall!
Update (5/27/09 at 6:40 pm): corrected the information when the photo was posted on Flickr, thanks to the reader Alvaro H. Martins. Thanks dude!