I absolutely love SQL (especially SQL Server) and I love how I continually find new ways to solve problems with it. I wish I could remember where I first found this tip to give proper credit, but I really love it.
Have you ever wanted to return a comma-delimited list of records in SQL Server? It turns out, that it is actually pretty easy to do.
For example, if you have users that can work in multiple regions and you need a list of which regions they work in.