So....apparently Han Solo was in Firefly. The miniature carbonated version anyway, stuck in the background of several scenes in the show itself. Being a constant presences of inspiration for our rugged Malcolm Reynolds, it seems. Oh Joss Whedon, your fanboying geekery amuses and delights me. *g* Because of this trivia I happily rewatched the episodes to spot them myself even though someone already did, since it's a nice excuse to what my shiny show again. I am such a Browncoat, heee.
Another piece of trivia: There was a Firefly class spaceship in the mini-series of Battlestar Galactica.
I also get a kick watching people's shocked reaction when they learn that Zac Efron played young!Simon on the show in his first acting role ever. ;)