How can I redirect a call, incall I want to get a call from somebody and after talking with him redirect that person to another number, on my charge, like call-centers do. Is that possible and if that's so, there is any application that can do that?

Thanks
I guess you could do this using the "Conference Call" trick on android (natively!). 

The screenshots below are for vanilla Froyo (Android 2.2) and may vary with your version/dialer app.

During your call (Don't hang up the call), after talking to that person, press the "Menu" button on your android. Press "Add Call" from the menu.



Dial and call the number you wish to "redirect" for him. (on your charge! (which is what you asked for right?) Means you will lose money for this call as if you are calling it)

Now press menu button again when call connects. Press on "merge call".



Finally, Press the menu button again and click on "mute" to make them think you have terminated your call. (you mute yourself but you can hear the conversation between him and the "redirected" call)



Remember, while doing these, you will be charged for 2 calls simultaneously!