Here's the pot (or planter saucer, hehe) of lawn grass that I grew using cotton balls that were stretched out to substitute for potting soil and a regular ol' planter saucer as a clear pot. Check out my thread if you want to know how to grow lawn grass right indoors in your home so that your piggies can graze on it right in the comfort of their own home. Best thing of all, you don't have to watch them while they're outdoors where there is predators and a lot of other dangers. I've grown neurotic that they'll suddenly get a bolt of courage and go storming off into the streets and get hurt by an oncoming car (I live in the city so I'm always worried about these things).