Very interesting post here. Only works in MS-SQL but it returns a list of data in a column in your query. I quite often need to do this but unfortunately it does create a function in the database itself. Still a great way of cutting down on queries on the page.
If you are wondering how you would use this. Well say you had a table of products and a table of categories and you wanted to retrieve the related categories in a separate column as a list, this function would allow you to do this. I can already think of many uses!