It's in the bag! (Property Bag that is...)
I've been working on a managed smart tag with a fairly complex XML payload and thought that wouldn't it be nice to automatically see if my XML string being generated correctly? So I quickly wrote the following code to use Word comments to annotate my smart tags xml...
Sub GetPropertyBag()
Dim st As SmartTag
For Each st In ActiveDocument.SmartTags
ActiveDocument.Comments.Add st.Range, st.XML
Next
End Sub