Lisa, when I told Steve you were outfitting your other bike to go grocery shopping, he said, "Doesn't she live on a big hill?"
I like this thread, too. I am not commuting now, either, but I still do some errands by bike. But, I just can't get into full grocery shopping by bike, because of my hill. I too, often ask why did we move here?
Right now I have one nice pannier on my Jamis Coda. It feels really heavy when I have it loaded, although with the mountain gearing, I do get up the hill and my driveway, very slowly when I have a lot of stuff.
My best story is when I converted my old Voodoo hard tail into a commuter last year. I decided to ride to the library (I go to the library in the next town, for a few reasons, but it's about the same distance as the Concord library). I had 3 books to return and two were heavy, 400 page books. I was amazed at how slow I had to go up the hill to the library; I walked in totally drenched with sweat. Then, on the way back, I have to make a right onto a busy road and immediately get in the lane to make a left and go straight up a hill. Now, I did this route on my old commute, but on my road bike. Well, I had new, lighter books in my pannier, but I felt so awkward, I had a hard time getting into the lane. There was a lot of traffic. I almost fell over and managed to get unclipped right before I stopped, pulled over in the shoulder lane. Then I waited until someone stopped and let me run my bike across the street.
The Jamis doesn't feel quite as awkward, but riding with a load feels really different. I go to this same library at least once a week to sit in the carrells and work on my papers, but I have hesitated to do this ride with my laptop in my pannier.
My favorite errand rides are to West Concord, to go to the natural foods food store, the bakery, the acupuncturist, etc. It's really only 2.5 miles, but because of the highway, I have to make it into a 6 mile ride. By the time I get home, those 12 miles feel like 20 after lugging stuff up the hill.