Be green and get some black (coffee that is) on April 22 from Starbucks.From the Starbucks website:That's right, just swing in with your travel mug and we'll fill it with our premium brewed coffee or tea for FREE. Don't have a travel mug? No problem. On April 22, all day long all of our travel mugs will be 20% off, plus we'll fill it with delicious brewed coffee or tea - on the house. Last year, Starbucks did a similar promotion on Earth Day and more than 1.2 million people that participated in the free coffee giveaway. Here's the Facebook invite if you want to make this a guilt-free mommy playdate.