Have you customized TFS?

I’m giving a talk at TechEd 2007 about customizing TFS. As part of that talk, I’d like to reference the real world experience of our users and I’m hoping you can help me here.  So, if you or your customer has customized TFS in some interesting way, I’d love to hear about it.  This might be a unique use for work item tracking, a cool new report, innovative check in policies, or a full-fledged customized process template.  Also, if you have tips and tricks that you think I should share, please send them on too.  Based on what I receive back, I’ll post the summary back here on my blog for all to refer to.