Hey,
I haven't read this one yet but I wanted to give the link as I've just
come across it.

Title: Make All the Rain Explode
Fandom: Supernatural/Stargate SG-1
Rating: PG-13
Pairing: none
Spoilers: Fragile Balance for SG-1, none for SPN
Summary: Sam is taken to be the host for a goddess.
http://jade-starlight.livejournal.com/116674.html