Original Series
The Gemini also appears in the Original Series as the ship where Cassiopeia is rescued in "Saga of a Star World."
Re-imagined Series
The Gemini is a freighter in the fleet assembled by Laura Roslin.
Notes
Interestingly, to the Colonials, "Gemini" is the ancient word for Gemenon. Why the ship's owners chose to use this ancient term (rather than the contemporary) is unclear.