[Wannabe]

Breast pumps designed for nursing mothers can help a bit in the breast size (or shape) department, I think, but they are not designed for that purpose and don't work very well for that. They typically have soft cups that are meant to fit down against most of the breast and create suction on the nipples. This can perk up your nips a bit, but it's doesn't do as much for the whole breast area. For that you really need the rigid cup that pulls forward the entire breast.

I have a nursing pump and used it on and off for a long time. It did help keep my nipples perky, but didn't do much other than loosen the overall breast area.