Per Tom Ogilvy:
http://www.contextures.com/tiptech.html

Under data validation, look at Dependent Lists.

Thanks. I started going through the sample last nite.

Having gotten hung up on "The worksheet range for the list data
must be on the active worksheet", I'm just putting the list data
on the same sheet as the "real" stuff until I figure out what I'm
doing wrong in that respect.

Excel 11.
--
PeteCresswell