As you probably know, "dogfooding" is the term we use at Microsoft for using the products we are building.
Inside Microsoft, our product is known as Ocracoke. Ocracoke includes web tests, unit tests (when used in a load test), and load tests, as well as the "rig" functionality (controller and agents).
As you can imagine, there is a lot of load testing going on at Microsoft. One thing the load testing team has been very successful at is getting internal teams to dogfood our product. We've actually had dogfooders since we completed our very first coding milestone in 2003. Now I'm not talking about our internal customers playing with the product and kicking the tires. I'm talking about teams using the product to do heavy duty load testing on their products. This has been an extremely valuable source of feedback for the team, as some of our more powerful features have fome from dogfooder suggestions, features like the load test plugin, user modeling, goal-based load pattern.
The list of teams is impressive -- teams from every division, and some of the most recognized products and web properties in the company are using Ocracoke to test their products. Here's a partial list: