Why Does The Post Office Deliver the Mail while the Royal Mail Delivers the Post?

Cafe Hayek on the argument for ending the Postal Service's monopoly on first class mail. Actually, they just quote the Baltimore Sun, but I refuse to link to them unless I absolutely must. It does seem like it's time to kill this billion dollar turkey.

Fun Fact: The USPS is the third-largest employer in the United States (after the United States Department of Defense and Wal-Mart) and operates the largest civilian vehicle fleet in the world, with an estimated 260,000 vehicles. (via Wikipedia)