At the DallasPHP meeting this month I gave a presentation called “Building from the Ground Up, Can Has Framewerk?”, where I discussed a bit about what gives a code framework its structure, highlighted a few popular frameworks, and then discussed provisions you should think about when planning to build your own framework from scratch.
To my suprise, the presentation lasted just over an hour and had some good question/answer time afterwards. Unfortunately the camera we used to record the meeting uses a FAT file system (or something) and quit recording after the file hit 4GB, cutting off the last 20 minutes or so of the presentation.
Here are the slides and demonstration code I used for the presentation!