The basic traveling commands listed above all ignore spypoints; the following commands take advantage of spypoints.
Zipping gives up some information in exchange for greatly increased speed. This is not always desirable, but sometimes is very helpful. A good use for zipping might be to run through a time-consuming initial part of a computation that is known to work properly, and stop at the beginning of a part that has a bug. From that point, you might use leaping, creeping, and skipping to locate the bug.