My recent "Windows Workflow Foundation: Tracking Services Introduction" article just went up on MSDN. I hope people will find it of interest. I wrote it for three main reasons:

Firstly, I wanted to delve a little more deeply into the subject, and articles are always good for that, as you not only have to be more rigorous, but you get peer and product team review, which is always very useful. So many thanks to Ranjesh Jaganathan, Moustafa Ahmed, Joel West and Paul Andrew.

Secondly, the early documentation on Tracking was a little disjointed and lacking in places and whilst this has now largely been resolved, I still felt a good introductory level article was needed.

Finally, Tracking answers a common question lots of people ask about Windows Workflow Foundation - "How do I look inside a workflow to see what is happening to it?". You don't - you use tracking to generate information as the workflow executes, and interrogate that. Read the article if you want more details . . .