Drupal - Multigroup (CCK3) / FlexiField-like solution for compound fields?

For the moment, I'm implementing this via Field collection. Granted, that is still very early development.

If somebody could provide a list of solutions in the "group content fields together and allow an infinite number of these groups via the 'add another' button", I'll accept that as my answer. I may have to upgrade my FlexiField project to D7 at some point and there's currently no clear upgrade path with that module.

Assuming you are using Drupal 6, there is a submodule called multigroup that allows you to group multiple fields together (creates the relationship) and gives you the ability to add unlimited values of each group.

If you are doing this in D7, you can use the Field Collection module, which does the same thing.