Just had a couple of ideas for treasures want to pass along to Herr Burt
#1) For a secret weapon reward you might want to consider extra T-bomb capacity (or nuclear space mines if they could be added to any race)
#2) I think one reward should be roleplay oriented where you get to save a "princess" or even a "harem" which might grant you additional piracy points but no effect on the map. Still would be fun for roleplay. As an interesting addition you could have 2 of this type of reward, one leading to a beautiful princess, and one leading to the recuse of a thankful and loving Gorn in a tutu
of course you wouldn't know who you rescued till the dead was done, and in the later case it could get posted on the forums for the enjoyment of all.
#3) Other roleplay related treasure maps such as the "Kroma" map above. For example instead of gold you might find the "Great Stash" of the Kzinti Patriarch, The recipe for Chocodiles, The enigma code of the SPQR, the Batleth of Kahless, A stash of old single-malt, etc.
#4) A genesis device that could be used to create a new planet or destroy an existing one (only 1 use of course)
#5) Corbomite, One use only of course
just some food for thought.