I agree that character driven B-plots are ideal for Star Trek games.
-The parents of one of the characters arrives to visit. The character then has to resolve the main plot while dealing with the problems his parents pose.
-The character is assigned to work with a visiting engineer/scientist/whatever who is exchanging ideas with the federation. This visitor has issues with the particular species of your character. Can the character maintain a co-operative air while being constantly belittled by the visitor?
- A rival of one of the characters from the academy arrives on the ship/starbase/whatever, and brings up the old rivalry, competing for the captain's attention/praise.
These are just a few I could think of off the top of my head.
Vince.
Don't fear the unknown
Revel in it.
Vinush
Y2K