Who doesn't have toilet paper rolls? Who saves toilet paper rolls? Everyone has them I know but most are tossed out or recycled.
here and made mine into squares.
I intended to make all of them into square seed starters by folding them in half, and in half again, scoring the sides to fold inward to form a bottom. It was easy but time consuming so I ended up using some of them in their original round shape.
All my tomato, cucumber, squash seeds did well in these and have been transplanted in the garden now. Only the Herbs are waiting to transplanted: Chamomile, English Lavender, Lemon Balm, Spearmint, Calendula, Scarlett Flax, Chia, Shiso, Parsley, Thyme, Sweet Basil, Oregano, Rosemary, Cilantro, Tarragon, and Sage. The clear containers are shoebox storage containers I found at Dollar Tree for $1.00 each. This was great for saving a bit of money in the garden budget and recycling.
Edit/Addition August 2011: Be sure to see this creative use of toilet paper rolls and tutorial for using them for art! -- from Monica Zuniga's blog: Hands and Heart.