Having played a bit on the new Beta 5, (assuming im not just getting this all embarrassingly wrong 
) and having played Civ V quite a bit recently, i was thinking that the way Civ V (BnW) does caravans (i.e. freighters) is pretty neat.
I always thought it weird in GalCiv you had to have a freighter travel 10's of turns to even start per turn income. It would make more sense, if doing it that way if it was a bulk amount (say 200bc on each arrival instead of 10bc a turn)
Like Civ V You just select a target and the money starts coming in per turn straight away. It could also be a normal sized ship to make it more obvious as a target like the Civ V caravans, but they dont show a fog of war and disappear if they go into it. Also having it attacked could be a much bigger prize / sting.
Gaining 200 gold in Civ V or loosing 10 a turn is a huge amount and something you need to provide real protection for if you are going into war.
You could also have the whole "get some of their science / impart your influence to that planet" thing going on.
Don't get me wrong, i don't think Civ V is super amazing or anything but i liked that aspect.
