How can I remove CA glues (e.g. Super Glue) from a material?
While superglue is strong enough to seal many things, it does have an enemy: acetone. Acetone is able to break down superglue bonds.

To get the superglue off of your shoe, try and use nail polish remover (that contains acetone). Be careful though, since acetone is known to be able to dry your hands quickly though. Using this should do the trick. Just remember, take your time, and wash off all the glue and nail polish remover when you are done. As acetone dries your skin, you may want some lotion handy.

As an additional aside, pointed out by CreationEdge, this won't work effectively on plastics, which it destroys, or other materials, such as wood, that may soak up the acetone.