You don't actually need a trainer for a nice cash injection - you can use the game's built in 'Game Editor'.
Along the top menu (under the message box) is a button on the far right - that's the Game Editor. It will load up whatever game you're currently playing and let you tweak tons of stuff.
For some extra money, load it up and then select the 'Edit Empires' button on the bottom of the new menu on the left hand side.
Select your Empire in the name list and then the middle Edit Empire button beneath. Here you have all the info on your space faring civilization - simply max out the 'Money' box (limited to 1,000,000) and then hit the 'Exit Editor' button on the left hand side menu.
Enjoy your ill gotten cash!
Yes, I know about the editor and how to give money but when you get midway to late game with tons of ships, colonies,expendatures, etc. your money goes fast especially if you have no trade treaties with others so it would be nice to have a cheat to hold the value at a certain figure.