I love schema collections in SQL Server. Very under-utilized by web developers who also use sql server, since they like to do everything with .NET, java, whatever.

At my last gig I had a project where I had to extract a large amount of data in xml format and ftp to a client or 3rd party and used a schema collection bound to an xml column as in this example to validate the xml prior to shipping it off. I also put the insert in a try catch and any errored out xml inserts I would push to an error table for analysis. Worked really well.