Walmart, the world's largest retailer, said on Monday they are looking to fill 150,000 positions nationwide and those taking positions in its fulfillment centers will earn $2 more an hour through Memorial Day. Fulfillment center employees, and hires that they refer, will also be able to each get a $250 bonus after the new employee has been on the job for 90 days. Other grocery chains and retailers are looking to add thousands of temporary employees to work in their stores.