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).