I have my iPhone modified to the point where "normal" people can't use it. Custom lock screens, no app names, blank menu screens due to "blank" app buttons, hidden menus only accessible by swiping on certain parts of the screen, etc. Not considered geeky here, but keeps most people from wanting to play with my damn phone.
I don't have the most powerful computer in the world, but I start it with a screw driver. Power button is dead and I haven't gotten around to fixing it. A screw driver isn't geeky by itself, but when used to start a computer there is a sliver of geekiness.
I won't count the many shirts I have since they aren't really a gadget. One of my friends does have both the WiFi signal strength, and drum set shirt that makes sounds t shirts though...what a NERD!