Assigning metadata or tags with an article

[pango]

Is it possible to make editors tag or provide metadata with an article?

One use-case would be:
- use the UserFrontEndmodule to assign some properties to the user: SendMeSMS which can be true or false
- then add a property for one folder called The Content" of Content with an textarea called "SMS Message" that is restricted to 160 chars

Whenever an editor add content the 'The Content' folder there should also be an "SMS Message" textarea where, if a message is typed, the content of "SMS Message" will be sent to the users that got the SendMeSMS property set to true.

Any advice, pointers to helpful modules would be appreciated!