In order to prevent someone from duplicating a key often hotels or office buildings use unique types of keys like some of those listed above in the section Different Types of Keys. No, it is illegal in most states to sell or possess burglary or entry tools. In order for a particular master key to work in a lock, the lock has to be set up to work on that master key. Locks are typically master keyed in hotels, office buildings, and schools. Rest assured that there is no such master key that opens all locks.
Most locksmiths advertise in the yellow pages.
Look for one close to you or one who clearly indicates he offers the services that you need. Check the ad to see if it indicates membership in a locksmith association such as the Associated Locksmiths of America. Membership in an association is not a guarantee of satisfaction. However, only the most conscientious business person takes the trouble to join a professional trade association. On the right is about x100 magnification and on the left is x2000.