The letter "U" is really tough to make a sound bin for. Remember, things like "unicorn" and "uvula" don't count because we are looking for the short-O sound. I still managed to pull together a respectable five-object collection with only one photo filling it out. We have the following: underwear, undershirt, underwater (are you noticing a theme here?), uncle, and umbrella. The photo is actually a photograph of Me Too himself swimming underwater. He thought it was neat that he found himself in a sound bin. The "uncle" is a popsicle-stick puppet of his own uncle. The miniature sound book has photo duplicates of everything you see as well as some things that are hard to represent as "objects" such as "upside-down" and "up."
The Alphatales book (AlphaTales Box Set) for this letter is easier to use than some of the other vowel's books. It was titled "Umbrellabird's Umbrella" and other than a unicorn or two, we didn't have to ignore a slew of long-vowel words. The book uses a lot of short-u adjectives which was helpful.