Mixing DataSource and a Collection in ListBox

Hey all,

I'm populating a ListBox with values from a table. I have the DataSet from
the table set up as my "DataSource" and I'm having no problem getting the
ListBox to show the items I want from that table. My question is: How do I
get the ListBox to display a row that is not in the table.

I usually program for web sites and having a default option can come in
handy. I just want to add something without a primary key value as the first
option of my ListBox.

Is there any hope?

Thanks!