>>I understand NULLS have a special purpose... but I think I'm starting to abuse it. For example, if we have a text comments area that saves to a varchar field, would it be proper to use NULL if the user left the text area blank, or would it be proper to use a blank string?
>
>
>To me nulls indicate the absence of data or choice. So if the user left it blank, there is no data.... ergo null. I don't think that you can overdo nulls.

I agree with what you say, although sometimes I view nulls more as "not applicable" state. In my example a comment is applicable, but not necessary. I think I need to adjust my thinking on nulls because viewing them as a not applicable state has led me to make some poor data modeling choices.