I'm having a hard time understanding exactly why someone would want to use their mobile phone as both keyboard and mouse for their PC, but I guess it could serve as an emergency replacement should something go wrong with your normal setup.

Alternatively, I could see phones replacing simple remote controllers (like the o­nes used in Windows XP Media Center Edition).

Quixun announced o­n July 5th that they have developed a system enabling the use of a mobile phone as PC keyboard and mouse.

This system employs the infrared communication function of a mobile phone, allowing it to control a PC from afar. It achieved by connect an infrared sensor to the PC via USB, and installing a special application o­n a mobile phone with an infrared communication function.

The keypress that is inputted to the phone is converted into a keypress for the PC by infrared sensor that is attached to the PC by USB (for example, pressing the "2" key twice o­n the phone will result in a keypress of "B" o­n the computer). Operation of the mouse, though not entirely finalized due to software specifications, will likely be emulated using the directional buttons of the phone. Customizations depending o­n phone model itself are also planned, such as coping with changing between keyboard and mouse mode, and dealing with different input styles such as that of NTT DoCoMo's "N901iS."

According to Quixon, the system is not just for key input/mouse operation, but can also employ phone functions such as communication and camera, as well as transferring URL data read from QR codes using the phone, and even AV remote controller functionality.

Inspired by:
http://www.itmedia.co.jp/pcupdate/articles/0507/05/news019.html

Press Release:
http://www.quixun.co.jp/press2/050706.htm