(written from a Production point of view)
William Smith is an actor who played several background roles on Star Trek: Deep Space Nine and Star Trek: Voyager. He received no credit for all of his appearances. His costume from the episode "Virtuoso" was sold off on the It's A Wrap! sale and auction on eBay.  His Ferengi waiter costume from Star Trek: Deep Space Nine was also sold off and worn by fellow background performers Alan Viner and Ken Ziff. 
In 1999, Smith appeared as a party guest in the comic adaptation Inspector Gadget along with Star Trek performers Andy Dick, Mike Hagerty, Rene Auberjonois, Richard Penn, Brad Blaisdell, Brian George, and Johnny Martin.