Amazon has Silk soy milk 6/5.99, free prime or super saver shipping. They have a few flavors available (this deal links to the regular kind):
Vanilla - http://www.amazon.com/Silk-Vanilla-Natural-Soymilk-32-Ounce/dp/B004HK46C2/
Chocolate - http://www.amazon.com/Silk-Chocolate-Natural-Soymilk-32-Ounce/dp/B004HK46BS/
Unsweetened - http://www.amazon.com/Silk-Unsweetened-Natural-Soymilk-32-Ounce/dp/B004HK7NTA/ (looks OOS atm)
For those who may wonder, soymilk in these containers doesn't have to be refrigerated until it's opened, so these won't monopolize your fridge or arrive spoiled.