So- I needed a battle plan.
I grabbed a store map that they have at the end of each aisle where I shop most often. I used it to create a complete master list of all the items I am likely to buy. The list, with check boxes beside each item is laid out in the order that I travel through the store. Now I go down the aisle and check off the list in order, as I go.
But the real clever part is this: The list looks all random, so it's had to find items to check off what you're filling out your list at home. So I copy/pasted the master list in Word, sorted it alphabetically and laid out the list on the other side of the page. I put it in a plastic sheet protector and attached a dry-erase marker and put it in the kitchen. Now, everyone in the family can check off what we need on the alpha list, and it's easy for me (the primary shopper) to quickly transfer the alpha list items to the store map list on the facing page.
Bonus: Since most household items are cheaper at a discount or drug store than at a grocery store, I made a separate list for those items.
It took about two hours at the computer to create the list and do the formating, but now I can do "big" grocery shopping (like eight reusable tote bags worth) in about 20-30 minutes - and that includes reading unit prices and using coupons.
Update: Since I originally posted this, I've started shopping multiple stores to take advantage of best deals, and I buy a lot more in bulk. That has reduced my speed but further improved my savings.