The Venn diagram in 2003 (at least) comes with "click to add text" boxes
outside each circle. So you can't select a circle and start typing, but at
least you don't have to draw your own textboxes -- you can click in the
existing ones and type in them. To move the textboxes on top of the circles,
turn off "AutoLayout" on the Diagram toolbar that pops up when you select
the diagram or an item in it.