I'm curious if GalCiv will ever add a cloaking device technology thread. It seems consipiciously absent from an otherwise comprehensive tech tree.
Cloaking devices wouldn't need to make ships 100% invisible, per se, but perhaps just cut down the range of ship scanners. For example:
'level 1' cloaked ship could only be seen at 50% of the range of a 'level 1' scanner.
'level 2' cloaked ship could only be seen at 25% of a 'level 1' scanner, or 50% of a 'level 2' scanner.
In combat, the cloak could just provide a general chance to dodge incoming fire which would go up with better cloaks or go down with better scanners. There could even be a targeting computer upgrade (and tech thread) designed to counter cloaked ships in combat (or something), but really it is well countered by sensor technology.