I displayed it much more when I was a kid. I had built the three main starships (Enterprise, Klingon Cruiser, and Romulan Bird of Prey) plus the AMT Exploration Set. I had a few Star Trek posters on my walls and a number of books on the shelves. And I'd visited the Federation Trading Post in Manhattan a few times. During summer camp, I built several phasers out of ceramics (type I and II), with one of them turning out fairly accurate (I'd used the Making of Star Trek book as a guide). When visiting some friends of my family on Martha's Vineyard, I'd accidentally left one of my phasers there. They thought it was a small model of a door.
I had a best friend who was also into Star Trek and we'd watch episodes together, chat about everything Trek and sci-fi. When I moved away, I ended up in a school with few Star Trek fans save for a couple of peculiar guys that I didn't relate very well to (one looked like a Vulcan (Spock eyebrows) and the other was a super-smart dwarf). Professing a love of Star Trek was grounds for scorn, ridicule, and teasing. So... I learned to hide it.
As an adult, I've got just the TOS DVD set and a few Master Replicas props. I have donned Starfleet uniforms for Halloween, complete with functional simulated props, but not for some time now. The models are all stowed away in boxes. About the only display of my Trekieness now is my phone... which sometimes utilizes various sound effects from TNG (doorbell for text message, holodeck door closing for voicemail). But if I do run into somebody that likes Star Trek, I'm always willing to chat about it. I recently clued in a few people about TrekBBS, and one of them was totally blown away by the caption contest comedies.
