That's my dad. He's retiring after 50+ years of working. He has always been an awesome dad. I cannot for the life of me think of a retirement gift for him. He loves everything to do with computers, robots, electronical doodads, really long fantasy novels, and Baen military science fiction novels (Honor Harrington, Miles Vorkosigan, ad infinitum). He also really likes books about building and making stuff (boats, robots, sheds, trailers, etc), but he seems to never make any actual stuff. He's also very shy and nonsocial, though he has a small circle of friends. He already has an ereader and really cozy slippers. And every tool known to mankind and every issue of Make Magazine. And a Robbie the Robot, a Robosapien, and a Dalek.
What would be a good gift? I like to sew and I am pretty handy with a hot glue gun, and I would make something if I could figure out what. I already sewed him a very cozy fleece blanket with Pogo embroidered on it. Advice PLZ!