"Near Field Communication (NFC) is the current hot issue in mobile computing.  It is a short-range wireless connectivity standard designed for simple and safe communication between electronic devices.  It operates over a maximum distance of 10 cm.  Currently, this technology is aimed for use in mobile phones only.  The characteristics of NFC make it a very promising wireless communication technology in the future.  With this technology, mobile phones can emulate a smartcard (e.g. credit card) for payment and ticketing and it can also act as a reader.  Thus NFC combines the interface of a smartcard and a reader in one device.  One major advantage of NFC over other wireless technologies is the simplicity of the transactions.  A transaction can be initiated by just touching another NFC compliant device."

Source: Wikipedia, NFC-Forum

 Here is a nice video to give you an idea of what NFC is all about: 

NFC in mobile payment : http://www.youtube.com/watch?v=2KTyFE3sfSo&feature=related
Catering service for elders : http://www.youtube.com/watch?v=4_xYMWqbGLM&feature=related
NFC in hotels : http://www.youtube.com/watch?v=pUHOOUBJr6s
Other interesting vid : http://blogs.forum.nokia.com/blog/video-library/2007/11/27/nfc-apps