The original idea for doing this came from the book Practices of an Agile Developer.
I started it sometime in 2006 as a WordPress blog on DreamHost. In that form, I moved it to Slicehost and then to WebFaction. On Webfaction, I converted it to Octopress. That still turned out to be a bit too much friction. Now I've started using Gists for this purpose. Most things I try to keep track of, I just create a Notational/Simplenote note.
I've made a point to move over the most popular and (what I find to be) most helpful posts. The rest can be found in the Octopress repository.