Bryce (bcammo) has modified my "no comment" forum to allow users to enter their name - but it is only used for Anonymous users and completely ignored when you are posting with a Wikidot account (your Wikidot username is used instead).

In cases like this, it would be useful to be able to show the field only to certain users.

Not sure how it would be implemented, but the ability to show a certain field to "only anonymous users", and other fields "to everyone except anonymous users" (the opposite, for completeness) would be extremely useful.