Get a free sample of Starbucks VIA Ready Brew instant coffee from Walmart. Look for the green “Get a Free Sample” button on the left side to get to the form to fill out. You should receive your sample within four weeks.
Find all the Walmart samples here.
Update 6/29/10: Got my sample and it included a coupon to Save $0.50 on Starbucks VIA (expires 7/31/10).