Following his amazing GLaDOS from Portal 2, Brandon Bannerman (Catsy) miniaturizes a turret to minifig-scale (or near enough), alongside an adorable custom Chell fig, complete with ASHPD.
For all of you out there who’d like your own turret to keep you company during the long twilight of civilization, Brandon has kindly posted instructions.
Another interesting thing about Brandon’s design has been watching it evolve based on feedback from fellow builders. See the earlier iterations here and here, together with the comments that inspired the final version.