How to tell our son's a Trekkie

At not quite 3, our son is already a Trekkie.  He wanted to be Tuvok for Hallowe'en, though I procrastinated on making the costume and thus that didn't happen.  Lately he's been talking about holograms a lot, and he asks to watch Star Trek: Voyager nearly every day.  No complaints here, since my husband and I are both Trekkies. :-)