Paper napkins
Freezer-burned vegetables
Burlap coffee bags
Pet hair
Potash rock
Post-it notes
Freezer-burned fruit
Wood chips
Bee droppings
Lint from behind refrigerator
Hay
Popcorn (unpopped, 'Old Maids,' too)
Freezer-burned fish
Old spices
Pine needles
Leaves
Matches (paper or wood)
Seaweed and kelp
Hops
Chicken manure
Leather dust
Old, dried up and faded herbs
Bird cage cleanings
Paper towels
Brewery wastes
Grass clippings
Hoof and horn meal
Molasses residue
Potato peelings
Unpaid bills
Gin trash (wastes from cotton plants)
Weeds
Rabbit manure
Hair clippings from the barber
Stale bread
Coffee grounds
Wood ashes
Sawdust
Tea bags and grounds
Shredded newspapers
Egg shells
Cow manure
Alfalfa
Winter rye
Grapefruit rinds
Pea vines
Houseplant trimmings
Old pasta
Grape wastes
Garden soil
Powdered/ground phosphate rock
Corncobs (takes a long time to decompose)
Jell-o (gelatin)
Blood meal
Winery wastes
Spanish moss
Limestone
Fish meal
Aquarium plants
Beet wastes
Sunday comics
Harbor mud
Felt waste
Wheat straw
Peat moss
Kleenex tissues
Milk (in small amounts)
Soy milk
Tree bark
Starfish (dead ones!)
Melted ice cream
Flower petals
Pumpkin seeds
Q-tips (cotton swabs: cardboard, not plastic sticks)
Expired flower arrangements
Elmer's glue
BBQ'd fish skin
Bone meal
Citrus wastes
Stale potato chips
Rhubarb stems
Old leather gardening gloves
Tobacco wastes
Bird guano
Hog manure
Dried jellyfish
Wheat bran
Guinea pig cage cleanings
Nut shells
Cattail reeds
Clover
Granite dust
Moldy cheese
Greensand
Straw
Shredded cardboard
Dolomite lime
Cover crops
Quail eggs (OK, I needed a 'Q' word)
Rapeseed meal
Bat guano
Fish scraps
Tea bags (black and herbal)
Apple cores
Electric razor trimmings
Kitchen wastes
Outdated yogurt
Toenail clippings
Shrimp shells
Crab shells
Lobster shells
Pie crust
Leather wallets
Onion skins
Bagasse (sugar cane residue)
Watermelon rinds
Date pits
Goat manure
Olive pits
Peanut shells
Burned oatmeal (sorry, Mom)
Lint from clothes dryer
Bread crusts
Cooked rice
River mud
Tofu (it's only soybeans, man!)
Wine gone bad (what a waste!)
Banana peels
Fingernail and toenail clippings
Chocolate cookies
Wooden toothpicks
Moss from last year's hanging baskets
Stale breakfast cereal
Pickles
'Dust bunnies' from under the bed
Pencil shavings
Wool socks
Artichoke leaves
Leather watch bands
Fruit salad
Tossed salad (now THERE's tossing it!)
Brown paper bags
Soggy Cheerios
Theater tickets
Lees from making wine
Burned toast
Feathers
Animal fur
Horse manure
Vacuum cleaner bag contents
Coconut hull fiber
Old or outdated seeds
Macaroni and cheese
Liquid from canned vegetables
Liquid from canned fruit
Old beer
Wedding bouquets
Greeting card envelopes
Snow
Dead bees and flies
Horse hair
Peanut butter sandwiches
Dirt from soles of shoes, boots
Fish bones
Ivory soap scraps
Spoiled canned fruits and vegetables
Produce trimmings from grocery store
Cardboard cereal boxes (shredded)
Grocery receipts
Urine (It's true! Read the letters below)

More "compostable" reading:

The World's Fastest Compost

How to Compost Dog Waste

Manure Matters: How different manures rate

What about urine? As promised, the letter from Jean in Scotland...