20 Things You Didn't Know About Serenity
8. The Film Was Marketed With Five Web Videos
Another piece of Firefly-related media is R. Tam Sessions (also called Session 416), a series of five web videos that were released alongside Serenity, as part of a viral marketing campaign.
The videos depict the counselling sessions between River and her therapist (played by Whedon, no less), while she is held at the Alliance Academy. It depicts her change from sweet young child prodigy to the character seen in the TV show.
So if you are looking for more material in the Fireflyverse, then there is plenty other stuff out there for you.