Automatically adjust font size in PowerPoint text boxes.

Actually, I do believe that if you insert a textbox in PP 2007 the default setting is to autofit the textbox to the text, not the other way around.  This option is controlled for the current text box by right-clicking it's border and choosing Format Shape, on the Text Box tab Resize shape to fit text is the default, but you can change that to Shrink text on overflow.

SmartArt shapes have as a default the behavior you desire.  You could use one of them and remove the formatting and delete the extra shapes, if you really wanted.

To get that list back, go to the View Tab and click Normal (even if it is already selected as the current view.) It will reset you to the default normal view and bring the slide list back.

(PS: Hate to admit it, but I tend to click the X that closes that pane more frequently than you would guess. For me it happens when I switch that pane from slides to outline. The X is too big... :) )