TED
You've heard of the TED conference? Well, this was the other TED, Ted Mielczarek to be exact. Ted came and shared his vast build knowledge with the students. Multiple people took notes for the talk. Ted did a great job showing us how things work, and giving insight into various processes. For example, he crashed his browser while doing the talk, and went through the process of using the crash reporter, searching for existing bugs, filing a new bug, finding that a duplicate did in fact exist, debugging the code, using bonsai, lxr, etc. It's the sort of guided tour that a new dev needs, and Ted did it gracefully.
Too bad for Ted the Canadian dollar went above the US in value on his one trip to Canada! You'll have to come again, I guess. Thanks, Ted.