Alright I've written a few theories myself (most of them out of jest) about things in the Naruto World. Post some of your own if you want. Go nuts here, ranging from the possible to insane.

Ex:
Tsunade is Naruto's Mom.
What we know is that Tsunade's Brother looked a lot like Naruto. And we know that Tsunade had a fling with a guy named DAN (what a great japanese name&#33 during the great ninja war. Plus she is about 50 years old, while Naruto is 13.
50 - 14 (9 months too) is about 36 which is plausible.

Another Ex:
Naruto is a fishstick in disguise - who so happens to be the distant relative of the fishstick that was eaten by the 4th - who choked to death by a bone in the fishstick. But before he died he managed to seal the Kyuubi and placed the seal on the fishstick he was going to eat next (NARUTO&#33 This imense chakra embedded in the fishstick allowed it to permenantly change into a real human boy. Now naruto is being secretly followed by a cricket named jimminee. For what evil purpose, who knows.