I'll sneak in before the thread gets moved...

The local (e.g. Pennsylvania) Price-Rite makes you bag your own - even charges 9 cents per heavy-duty plastic bag (the idea being that you will reuse them). Your purchases are placed into antoher cart as they're checked and then you go to a bagging shelf to bag them after you've paid.

We just wheel the cart to the car and dump it all into a cooler in the trunk.