A quick tip for a Friday afternoon. Let's say you've been working on your Umbraco site for a while, and there's a version on a server somewhere that the client is using. You need to add loads of attributes to an existing document type (exists on both versions). It's a pain, because you have to do it locally, test your layouts, etc, and then re-do your changes on the server (I'm assuming that you don't have access to the Courier tool here).

Well, actually, you don't. Just export your document type from your local install, and import it on your server, and it will magically overwrite the existing document type! This means that existing nodes that use that document type now have all of your new attributes!

Disclaimer: this has worked a grand total of once for me, so be careful! Also, I have no idea what happens to your data if you change existing attribute types - this worked nicely when I had to add many new attributes. As I said, this is a quick tip! Use at your own risk!