Just in case anyone is looking for a cute dress, I wanted to post about one I recently bought. I think it looks great on hourglasses, and when my mom saw mine she actually bought one as well (she is an hourglass/pear, and does have a little belly pooch, but this dress hid everything). There is boning/wiring in the bust of the dress, and the straps are thick enough to easily wear a bra underneath.
I actually bought it at full price but still haven't worn it, and it has gone on sale so many times since that I have had a price adjustment and a series of times when I returned it and rebought it at a lower price. At $37, it feels like you can't go wrong.
Here it is: http://www1.macys.com/catalog/.....sn_results