Although I decided against using a listbox and simply just using a subform, I did spend a lot of time trying to figure out how to get the listbox to store more than one values for that field. If the listbox multiselect property is on "None", it stores, obviously, the one and only value selected. However, when I enable either "Extended" or "Simple", it stores none of them - no matter if its one or more.
Based on this, it is my impression that lisboxes are more effective for queries rather than selection and data entry.
The reason i bring this up is because I was trying to create a matrix with multiple values. For example:
A B C
John x x
Bob x x
Tom x x
Like I said, I used a subform with checkboxes. But I am still very curious as to how to multi-select listboxes can store values.