Endpoint.tv Talks Tracking
I heard that the folks that bring you endpoint.tv are doing a two part series on Workflow Tracking in 3.0/3.5. This is one of my favorite feature areas in 3.0/3.5, and one that I think is not talked about too often. The team built a lot of functionality in there besides the very basic "emit tracking info" one might expect with the feature description.
Check it out, and if you want some other background, check out these blog posts I made a few years back!