We've bundled these bags together for you.  Now we are moving to ban plastic bags, this sort of bag is becoming essential.  The shopping cart opens and the wheels lock into place, and then it can collapse down again for stowing in the car trunk.  

The Vernon tote is a decent size, large enough to take a Samsonite laptop bag. 

The Samsonite laptop bag fits snugly inside the Vernon tote, but could be used as a carry case alone.