This was going to be a response to amberlynne's comment but it grew out of control. On the topic of subverting fannish tropes (sort of) and John the non-Sudoku-Master:

As I told eleveninches once, what I really want to write is the one where John isn't just weirdly good at manipulating Ancient technology -- he's actually *trans-specied*. He's an Ancient trapped in a stupid human body! He's tragically genetically queered! He longs for gray jumpsuits and shifty scientific ethics and the chance to play The Sims with whole human civilizations!

Or, hey! What about the one where John SUCKS at activating a particular Ancient artifact? Like, everyone with the ATA gene can do it except him! And it's an Ancient bean grinder or something so it doesn't *matter* but it's making him batshit insane that he CAN'T DO IT. And he carries it around in his pocket and ducks into supply closets and tries with all his ATA might to get it whirring and the device *ignores* him, the blatant hussy of an Ancient thing, and he's all wounded and bewildered and Rodney has to comfort him with sex. And more Ancient toys.

ETA: Or! OR!

The one where John TRAVELS BACK IN TIME to Ancient Atlantis and discovers so many interesting truths, like:

1) The entire expedition has been bunking up in the children's boarding school part of the city, which is why all their beds are 2 inches long.

2) John is actually not that Ancient and they all think he's kind of adorably dumb and ignorant and they treat him like a kid and muss his hair.

3) The puddle jumpers are actually not fighter shuttles. They are, in fact, Ancient yellow school buses. The cool fighter shuttles are over in the east wing where the expedition hasn't looked yet.

Other fun Ancient facts? Come on, it'd be AWESOME.