If you have, or had kids then you most certainly have a box of cruddy crayons hanging around! Not only are they easy to find around your own house, these crayons are often available by the box from garage sales for a pittance. You needed worry about how used they are, people often buy these for crafts, to melt down, etc. Crayons in bulk typically sell for around $5 a pound plus shipping. (Plus they won't be used to write on your walls anymore. Maybe you should sell those sharpies while you're at it?)
Empty Wine Bottles
Selling empty wine bottles can do anything from letting you buy more gas station wine, to helping you make your rent payment. Depending on the age, rarity, and make of the bottle, empty wine bottles can go anywhere from $1 a piece to well over $100 a piece. So next time you're going through someone's cellar (your parents maybe) don't throw away those bottles away!
When i was a kid, I actually used egg cartons to save and count my money in! Turns out I should have just been selling the egg cartons instead. While they won't make you rich, if you eat a lot of eggs around your house, you're much better off saving the cartons for eBay than throwing them away! You can make at least $0.25 a carton! Now I just need somewhere to store them...