I also have used every posible container for starting seeds. I use those plastic tub containers that hamburger comes in...I sterilize them after washing very good. I make drianage holes in the bottle of the container, the ones I use fit nicely into a gallon recycled zip lock freezer bag, you can write on the plastic container or the ziplock bag. When the seedlings have sprouted and have their first or second set of leaves, I transplant each one into strofoam coffee cups..the larger sized ones. The styrofoam cups are easy to write on also and you can recycle them or tear them up when you transplant outdoors, I have never had a problem with mold using these cups, but I also have a fan blowing on the plants to keep good air flow and I also bottom water. I do not like the peat type pots, as they do not seem to break down as they are said to, there fore they do not allow the roots to grow like they should. The jiffy pellets are alright, but for me they wouldn't work, since I start my tomatoes very early and they are very large plants when I set them outdoors. Here are the size mine are when they are still indoors:
