Cork stoppers can be found in various retail locations beyond online shopping. Local wineries and wine shops are recommended sources, as they often sell corks and related supplies. Big box stores like Walmart, Home Depot, and Lowe's may carry corks, though the selection might be limited. Specialty stores focused on winemaking supplies could also have what you need, although they are becoming rarer. For specific needs, such as stoppers for panpipe tubes, alternatives like rubber stoppers or DIY solutions using materials like silicone or wooden dowels are suggested. Hobby shops may also stock cork and other materials suitable for crafting custom stoppers. When searching in hardware stores, it's beneficial to describe your needs to employees for potential solutions.