Jason (As well as Morton) wear glasses similar to Dave.Both Jason's and Morton's glasses are opaque. Thus, both sets of glasses have H.U.D's in them. They are nerds, after all. Not all glasses in the strip look like theirs. Phoebe's glasses are transparent. Thus, theirs are special.
Jason is an armoured-closet transgenderist.Think about it; he's afraid of being seen interacting with girls to an extreme and impractical extent, even for a ten year old boy. But the real evidence comes from his dream sequences; one seems to suggest that, at some subconscious level, he has a repressed desire to be Lara Croft; another time, he dreamt that he turned into a girl and started to like it.
Jason is a Time Lord.His TARDIS is the iFruit. That's why he's often on it, and also why Paige knew who was voted of "Survivor", Peter read the next day's "Doonesbury", and Jason downloaded the "Attack of the Clones" soundtrack 2 weeks early, all from the iFruit in one strip. Whenever the year ends, he travels back in time to the beginning of it, because he's comfortable being 10 and never wants to grow up, hence why no one ages. The reason many current events and movies occur in the strip is because Jason travels to the future to witness them. Oh, and the last panel of this strip wasn't imaginary- it was Jason traveling 11 or 21 years in the future to see his grown-up self.
Jason will eventually (like when he's an adult) travel to other Universes.Whether this happens or not you have to admit it'd be pretty cool...especially if he ended up in Fallout.
Jason is Milo Bloom.They are both skinny, short, nerds who wear glasses. They're both from popular Newspaper Comics, and they both have blond hair. Compare this◊ with this◊.
Jason and the Peanuts characters go to the same school.Come on, the Peanuts characters HAVE been seen in Foxtrot on two occasions.
Bill Amend is a Brony
At some point after her final appearance, Denise regained her eyesight...and promptly broke up with Peter when she discovered what kinds of posters and calendars he had in his room, hence her vanishing entirely from the strip.