The longer its on there, the worse it gets. But heres a couple methods from a Webcrawler search...
Method One - Commercial Stain Remover
Saturate the dirty area with pretreatment laundry stain remover. Wait one minute for the product to penetrate the stain.
Method Two - Vinegar
To remove coffee (and chocolate stains), mix one teaspoon of white vinegar in one quart of cold water. Sponge on stain and wipe clean.
Method Three - Egg Yolk Solution
Mix the yolk of an egg and a few drops of alcohol with a little warm water. Rub mixture on the stain with a sponge.
Method Four - Baking Soda
Sprinkle a little baking soda on a wet dishcloth to quickly remove coffee and tea stains.