Like many city residents, we don't own a car and we jokingly refer to our stroller as the SUV because it practically functions like one for transporting the kiddo and lugging around groceries and dry cleaning. Our stroller has a large under-basket but we sometimes still have overflow (especially after a trip to Trader Joe's), so we've taken to using a stroller hook to carry a few more bags. The problem with our hook was its tendency to slide around on the handle causing the bags to knock us in the knees over and over. Now that we're converts to Think King's Mighty Buggy Hooks which stay in place we can report that our knees are blissfully unblemished.
Think King's use of velcro fasteners is a simple, but effective improvement. You can tighten them to fit any part of your stroller securely. And unlike the carabiner-style clip of our old hook which required two hands to use, the U-shaped hook of the Mighty Buggy Hook lets you just slip your bags on quickly with one hand. Think King sells their buggy hooks (2 for $14.95) on their website where you can also find a list of online and brick and mortar shops carrying them and their soft buggy cup.
Maybe someday we'll have a car with a big trunk we can load up, but for now we're happily making do with our SUV and buggy hooks.