Lemon juice, peroxide, baking soda and vinegar all work sparingly. Make sure that you test the fabric before using any of these products.
One of the best books that I have found on laundry care is Talking Dirty Laundry with the Queen of Clean.
Visit her website here: http://queenofclean.com/
Another one of her books specifically for spot and stain removal is The Queen of Clean The Royal Guide to Spot and Stain Removal by Linda Cobb.