A re-cycled steel container from Steel Life, this one is called the Mezzo Mod Dish, at 10x10" and just 4.5 inches high. Designed by Shannon Lester, a landscape designer in central Oregon. There are two other sizes -- one just five inches high and the other 7.5 inches. Colors include red, orange, white and lime green in addition to blue.
Lester's Shallow Root Vessel is 20 inches high and is available in red, orange, blue, and white. It's powder-coated steel and can be ordered with an optional hole in the bottom for drainage. All of these containers are made by local artisans, and Lester's vision for a xeriscaping container was reportedly inspired by gold panning trays she spotted on a trip down the Rogue River in Oregon.
Also, don't miss the unique "living wall" custom-made vessels that are made from patinaed steel. And check out other containers that might suit your needs on the Steel Life website.