I walked away from the computer thinking about this, because you’re creating a new type of custom field….
You might want to think about having a choice of things to return, the stylesheet url… maybe the script to call in some way. This is going to be a hard one because as a developer using you’re field type I’d want to be able to determine where I put it and how the value is used, on the other hand, if done by using a script then you’d have to have some way to ensure the script that loads up the styles heet into the header is only loaded once.
Creating a field type is about outputting a value that another developer can use for something. Not sure how you’re going to work that out.
