How do you remove adhesive?

I use a product called "Goo-Gone". It's an oily orange substance that smells of petroleum. (I'm in the United States.) I've found that very non-polar solvents like oils (Goo-Gone, gasoline, mineral or vegetable oil) dissolve most adhesives, but there's always stuff like superglue that dissolves in acetone...

Orange oil, Goo-gone, or turpentine, those are my recommendations :-)