Garlonuss

Chosen answer: Yes, he developed a way to test for Cylons. He even figured out Boomer was a Cylon, so we know it works. But in a later episode, he specifically tells Head 6 that he hasn't been doing the testing that he claims to have done because he actually prefers not to know, because it only breeds paranoia and fear. His opinion of Cylons is, after all, not typical.

Garlonuss

Show generally

Question: How does Number Six appear in Gaius Baltar's' mind? Is she a vision of some kind? Does he have a chip inside his head? Or is it something else entirely?

Socks1000

Chosen answer: Well, that's one of the big questions of the show and it's answered in the final episodes. She's, to use Baltar's term, an "angel". Beings who appear in the form of loved ones to help and guide us. Most of the time, they only appear in the head of one person, but the final season had one angel that everyone could see and interact with.

Garlonuss