I use the one from the hospital, I think it's the Similac one LOL. I just keep it stocked with a few outfits, diapers, wipes, and washcloths - DD has reflux and it can get messy often. I also use it as a "purse", so all my stuff is in there, wallet, checkbook, pen, whatever. I keep a bottle in one pocket, and my cell phone in the other. I change out the diapers when she goes up a size, and change out the clothes when I do a sweep through her baby clothes to put away the small ones.

__________________

I have one stocked in my car.
But to just run in the store what more do you really need but a diaper and some wipes. And for my toddler snacks.
*I usually fed mine in the car before I went in and preferred to change their diapers in my car as well.

__________________
"Before I was a Mom I didn't know the feeling of having my heart outside my body." ~Anonymous