Kangaroo Korner sells adjustable pouches in fleece, cotton, Solarveil, and mesh. The pouch has four rows of snaps and is available in 4 sizes. A sizing chart on the Web lets you determine the best fit, and the company recommends you get a slightly smaller fit so that you can tighten the snaps as the fabric naturally stretches. Depending on the fabric, the pouch can hold children up to 40 pounds. A variety of colors and patterns are available and two fabric types are waterproof. The pouches are handmade in the United States.

The construction is very good and the color selection is nice. It is very simple to place a baby or child in the pouch - no wrapping or tying required. The pouch can be used several different ways, including wearing the child on your back. The pouch is designed to drape over your shoulder so the weight is spread across your back, rather than on your shoulder. All the advantages of baby wearing apply; my 9-month-old loves to be in the sling and it keeps my hands free.
You can get it here: Kangaroo Korner