This one is a good one: http://www.reddit.com/r/serialpodcast/comments/2s3tty/thought_exercise_my_shortest_path_theory/

Here's a broad outline of my own "shortest path" (fewest/smallest leaps in logic) theory: Ignoring all of the soap opera characters that are Krysta and Cathy and Inez and the nurse, etc. Setting aside motive, since that's a sticky, subjective point for both Adnan and Jay. Adnan and Jay are together in the middle part of the day on 1/13. Adnan sees no issue with Jay borrowing the car and/or phone since he knows he's at school the rest of the day. (class, library, track) By circumstances we do not understand, Jay kills Hae roughly between 2:30-3:30pm. Jay and Jenn, in every statement and trial transcript, insist Jay was at Jenn's house until "around 3:40pm". The insistence is one of the few consistencies in Jay's statements. incoming call just before 5 is Adnan from school (school phone, payphone or friend's cell) for pickup. Jay picks up Adnan around 5:30, they are together hanging out (at cathy's, maybe Patapsco park, among other places) until around 7 when Jay drops Adnan at the mosque. Jay immediately calls Jenn to help facilitate him burying the body in Leakin Park. The timeframe is tight between dropping off Adnan and getting to Linkin Park, but it's possible that the calls were made as Jay was driving, in other words he didn't need to be stopped at the burial site, just on his way there. They bury the body and dispose of the clothes and shovels basically the way they describe, only it's Jay and Jenn's fingerprints they are destroying, not Adnan's. Jay returns Adnan's car to the mosque before or around 9 (with the phone). It's unclear if Jay and Adnan hang out again. It's possible, or Jay may have just left the keys under the floor mat for Adnan at the mosque. Adnan is stoned (courtesy of Jay) and clueless. Jay was a quirky guy and Adnan may not have noticed if Jay was acting differently than normal. What started as a conversation between casual acquaintances/friends (Jay & Hae) escalated and before Jay knew what happened Hae was dead. The trunk pop happened—only it was Jay popping the trunk on himself at the burial site, and seeing again the horrific image of Hae. This would have been traumatic even if he were alone, we need not assume it was Adnan who terrorized Jay with the dead body. Bonus wildcard side theory: Mr. S saw activity that night in LP and came back to see what it was. He's the one who put the stones on top of the body, believing it was the best thing he could do to honor the victim short of getting involved in the investigation, only later realizing that his tampering with the scene could have linked him to the crime, which is why he came forward. I would never call it a perfect theory, but it's primarily based on: assuming Adnan's alibi, though weak, is true enough that he was not with his phone for parts of the day, and the call logs.