I suppose it's useful to wear a hat that makes your competitors die laughing. I have two hats I use when faced with particularly difficult technical challenges. If the challenge involves detective work, I put on an authentic deerstalker, which makes its wearer feel like Sherlock Holmes. If the challenge involves exploration, it's time for the pith helmet.
Traditional, yes, but effective.
Max, if you want sparks, nothing says sparks better than Jacob's ladder. That is, if you are comfortable having a few kV's that close to your brain. You could end up like the guy in One Flew Over the Cuckoo's Nest!
My ultimate geek hat would be this one:
(Or, you can just search for Johnny Mnemonic's helmet.)
I think I remember that episode! Didn't it have sparklers on top?
The pyrotechnics were very effective, but I think these days it would bring the wrath of the Fire Marshall down upon you if used in a public place.
Re-viewing the episode (a friend has all the episodes of the original series), the Time Helmet has a small 'box' on each side from which extend backward three slender rods which seem to burn somewhat like sparklers (though they are larger than the fireworks I encountered as a child). It also had a barber pole that rotated, a dial to set the destination, two rods that extended upward (each having a short cross bar near the top) and were connected by a couple of wires, and a helical wire that formed a tall arch above the helmet (but below the two rods).
(http://www.twilightzonemuseum.com/show/images/3onceupon.jpg shows it [inactive] in the lower right corner of the picture.)
The episode is perhaps most distinctive in starring Buster Keaton and having the 1890s sections shown as silent film (with intertitles).
Yes, activating a Time Helmet indoors would be frowned upon.