To celebrate the Mac’s 21st birthday, the folks over the Joy of Tech comic have launched a special giveaway. Prizes include a Happy Computer embroidered t-shirt, and the widescreen special edition version of Dazed and Confused and Fast Times at Ridgemont High (both DVDs movies portray the era the Macintosh was released). They’re also giving away a copy of Open Water, (the disturbing tale of two divers accidently left out in the open ocean), shot entirely on digital video and edited on Macs.