CCK's standard "Display Fields" settings are good for configuring per-content type field visibility and can save a lot of custom coding time. If a field is shared over a dozen content types, however, a change to one has to be made to the others, and that's a lot of clicks.

The Content Type Selector module adds a little dropdown to the right of the tabs on the CCK settings pages. So you change the field settings on one content type, pick the next type in the dropdown, change it there, etc. It's still a lot of clicking but it's a few seconds trimmed with each page and feels more seamless.