Myoplex protein shakes.
42g of Protein and 300 calories (not bad).
I bought the 4-pack at walmart for ~$11. Somewhat pricey, but I wanted to try them. I was gonna take one to school with me every wednesday after I lifted. However, I drank all of them within 4 days. They tasted amazing! I was shocked at how delicous these were. When I'm busy during the summer, I will deff. be taking these with me when I'm on the go, regardless of the price. Well worth it in my opinion.
If you have some spare change lying around, go buy some at walley world, and enjoy!