Phebe wrote:

Perhaps I wasn't clear. I already have categories assigned to
contacts. What I'd like to be able to do is include all contacts with
a given category in a distribution list without having select the
contacts individually.

Don't use DLs. Instead, since you already have categories, use them.
Select a category and click ActionsNew Message to Contact to create a
message to all members of the category.
--
Brian Tillman