Photo by Hil
Again, this could be pulled off easily with a cardboard box "monitor" and a flat cardboard "keyboard" across your chest. But are you willing to take the easy way out? Why not try to fashion a recognizable version of an iconic bit of computer hardware, like the original iMac? Or those with a more historic bent might want to go as an old-school mainframe. Bonus points for actual rotating reel-to-reel tape.