There are lots of mobile apps for converting your phone into a remote, some works on bluetooth technology and some works on internet technology i.e., you can control your PC from anywhere in the world. But in most cases we prefer a local remote to control media players or just to do a PPT.
For Sony Ericsson phones, its very simple, just pair your phone and PC and go to applications and start using your phone as a remote. But you will not be able to get some features like Keyboard
For phones like Nokia, Samsung and other Java capable handsets, all you want to do is to install a Java app on your mobile and install a server side app on your PC.
Mobilewitch Bluetooth Remote Control
This is a free software. This software consists of two parts
1. A Java app for mobile (Client)
2. A java App for PC (Server)
Download Mobile witch Bluetooth remote control
Download and install Mobile Witch and follow the below steps
1. Start the application on PC,(Waiting for incoming connection)
2. Start the application on mobile