>I think the reason we don't use logical .T.'s and .F.'s is because we can have N-NO, Y-YES and U-UNKNOWN in most of our Y/N fields. Otherwise, I would prefer T/F for sure.

Null will allow for a third state, though, using a CheckBox is harder because the thrid state can only be achived via code and not User Interation. Wat you could do is build a combo with Two columns, one for display (Yes;No;Maybe) and bind it to (.T., .F., .NULL.)