Yes, most Grocery stores sell stamps. You can usually get stamps right at the check out lane, or going to customer service.
You can also purchase postage stamps online at Stamps.com and get FREE postage!
Grocery stores like Kroger, Publix, Wegmans, Tops, Stop & Shop, ShopRite, Food Lion, Albertsons and many other grocery stores all sell stamps.
To find USPS stamps at a grocery store near you, just type in your zip code here: http://www.uspseverywhere.com/