I saw this on THR:http://www.thehighroad.org/showthread.php?t=731730&highlight=chrome#post9158179
Walmart.com inventory "hack" for Google Chrome
Basically, you change one style on the page (STORE_MSG) and it will show you stock in your local store or allow you to click on the "Find in another store" link instead of just "Store information not available."
I doubt walmart.com's accuracy for store stock is perfect and there are likely some legitimate reasons for walmart to hide this information. I decided not to try driving to South Jordan (from Orem) for .22lr even though the site says it's in stock. But it was neat, so, enjoy.
ETA: This works in Chrom(e|ium) or Firefox for me.