411 USA
411 calls in the USA have been around for many years. 411 is the directory assistance number, serving as an automated version of the white and yellow pages. For a long time 411 calls were free, but in the past twenty years they have become charged calls.
In the US 411 is the local directory assistance number. There is a national directory assistance at 1-(area code)-555-1212. In the era of cell phones this is less of an issue than it was previously. All national cell carriers provide national directory assistance when a cell phone user dials 411. However for land lines, your local phone company routes you to their 411 system, where the national system is accessible with the 555-1212 number.
New technology has found new uses for 411 directory information. For instance you can now find the owner of a particular telephone number. Want to know who the person who called your cell phone at 3 am is? Simple, just place a reverse 411 directory lookup and the name and address of the owner of any phone number is at your fingertips.