What about egg cartains for starting seeds? Cottage cheese or yogurt containers would also work. Poke a hole in the bottom and use the top as a saucer. Coffee cans are also great. My mother saves the bags she gets from the dry cleaners and uses them to cover plants when she goes away. The plastic bags can keep the plants moist for a couple of weeks, so why not use them for starting seeds? I used to use plastic gallon jugs as a cloche for tomato plants when first planting them outside in the ground. It kept them warm while hardening them off so that they could adjust to the outside climate. It also helped the plants retain moisture.