Have you ever tried Goo Gone? I love the stuff. It gets all the dirty gunk (like from adhesive price tags) off things. If you wash a name tag or sticker on your kids clothes and the gunk won't come off, Goo Gone will take it off. It also says it takes off things like gum, crayon, grease, and tar. The great thing is that I found the small bottles of it at our local Dollar Tree (in the hardware aisle and cleaning product aisle)!
My sister is the one who told me about this stuff. Thanks Chris!