Okay, when I turn off my chat, the sidebar list goes back to the original set of people that are in my Ordered Friends list. However, when I turn the chat on, the list in my sidebar changes. This makes me think that the Ordered Friends list has something to do with the probability that you will chat or interact with that person based on a culmination of activity involving that person. However, because some people on the list I barely interact with, this leads me to believe it has something to do with how many times that person has viewed not your profile, but things like your statuses or pictures and vice versa. So, from what I'm seeing, the chat box is only related to the Ordered Friends list and not the sole purpose of it. Based on my research, I've found that basically, the Ordered Friends list has everything to do with interaction over a period of time based on a specific algorithm used to determine likelihood of interaction between two parties, which, in this case, is you and one of your friends. People might want to disprove my theory by claiming that they haven't chatted with or interacted with some people on their Ordered Friends list in months. Only two things could disprove this claim: 1) It is an algorithm based on culmination of activity over a period of time (it can be assumed that this period of time is recalculated every so often do to the ever changing state of Facebook) and 2) It has not only to do with your interaction with those people and how many times you look at their profile, like their statuses etc., but by how many times they do the same for you. This would also partly prove the theory that the Ordered Friends list has something to do with how many times a person has looked at your profile- granted it's over the period of time that the algorithm uses to calculate the list. Which means that people who you've just added could be high on the list because they would be within the time period of the next calculation.