Nephthys is an important character in the Kane Chronicles books by Rick Riordan. Without her knowledge as the bad guy's wife, the Kane kids wouldn't be able to defeat Seth.
In New Zealand, there's an entire family of marine catworms (segmented predators that dig into the sand) named for Nephthys. Back in ancient Roman times, she was sometimes associated with the sea (along with her husband Seth), so maybe it makes sense?
We'd be surprised if there weren't a death metal band named Nephthys.
Most images of Nephthys include a strange goblet-like object on her head. It's not a cup, but the three-dimensional hieroglyphs for her name: a round basket (nebt) on top of a tiny rectangular temple (het or hut). In Egyptian, this means "lady of the house/temple" (nebthet or nebthut), and is her name. The Greeks pronounced and spelled it Nephthys.