I believe there is a common misconception that it is illegal by Federal law to travel interstate with a concealed handgun if you have a concealed handgun license on a common or contract carrier such as a private bus service.
Those who believe it is illegal point out this law:
Those people who believe this is illegal say that for it to be legal, you have to hand over your handgun and ammunition to the pilot/captain/conductor/operator. However this exception is only valid if the person in possession of the handgun is only doing so to accompany it's transfer.18 USC §922 Unlawful Acts
(e) It shall be unlawful for any person knowingly to deliver or cause to be delivered to any common or contract carrier for transportation or shipment in interstate or foreign commerce, to persons other than licensed importers, licensed manufacturers, licensed dealers, or licensed collectors, any package or other container in which there is any firearm or ammunition without written notice to the carrier that such firearm or ammunition is being transported or shipped; except that any passenger who owns or legally possesses a firearm or ammunition being transported aboard any common or contract carrier for movement with the passenger in interstate or foreign commerce may deliver said firearm or ammunition into the custody of the pilot, captain, conductor or operator of such common or contract carrier for the duration of the trip without violating any of the provisions of this chapter. No common or contract carrier shall require or cause any label, tag, or other written notice to be placed on the outside of any package, luggage, or other container that such package, luggage, or other container contains a firearm.
EDIT: txmatt points out that this applies to commerce. So if you're not selling your handgun or ammunition, this law does not apply to you.
EDIT: Keith B points out that traveling to work may be considered commerce. I counter that almost any reason for travel could include commerce. So unless the handgun and ammunition itself is a part of the commerce, I still don't think this law applies.
Remember, everything after the word "except" is conditional that everything before the word "except" is met.
Everything in green I meet, until the red part, is not met by a person with a concealed handgun and a concealed handgun license, because the firearm and ammunition is not going to another person. The word "deliver" is used because this is talking about a delivery person. This becomes clear in the section after the "except" in blue EDIT: (wording is a passenger attached to a handgun, not a handgun attached to a passenger). EDIT 2: Actually, it just depends on the definition of "with"

It might help if the law is spaced so that it is easier to follow:
It shall be unlawful for any person knowingly to
_____deliver or cause to be delivered to
_____any common or contract carrier
_____for transportation or shipment in
_____interstate or foreign
_____commerce,
to persons other than
_____licensed importers, licensed manufacturers, licensed dealers, or licensed collectors,
_____any package or other container
in which there is any
_____firearm or ammunition
without written notice to the carrier that such
_____firearm or ammunition
_____is being transported or shipped;
except that any passenger who
_____owns or legally possesses
_____a firearm or ammunition
being transported aboard
_____any common or contract carrier
_____for movement with the passenger in
_____interstate or foreign commerce
may deliver said
_____firearm or ammunition
into the custody of the
_____pilot, captain, conductor or operator of
_____such common or contract carrier
_____for the duration of the trip without violating any of the provisions of this chapter.
No common or contract carrier
_____shall require or cause any
_____label, tag, or other written notice
_____to be placed on the outside of any
_____package, luggage, or other container that such
_____package, luggage, or other container
_____contains a firearm.