I have a trailer, and do use it on occasion. However, I find that for grocery runs, I usually just use panniers. The trailer is a bit cumbersome (and it's by far the best one I found). When we lived in Wilmington, I used it more. Hauling recycling, 8 12 packs of diet soft drinks (no, I don't drink them much anymore) etc. I have hauled a gallon or more of milk home in a pannier. My only problem is in the really hot summer - I haven't found a good way to insulate the stuff that needs to stay cool.
Most days in life don't stand out, But life's about those days that will...