I have a Samsung LNR409D 40 inch flat screen TV with an RGB jack for
displaying a video signal from a PC. How can I make it so that my
laptop is hooked up cordless to the TV flatscreen so that the TV will
show the same image as my laptop's screen? I basically want the
flatscreen to work as if it's my laptops screen, but I want the
connection to be cordless. I also would prefer for this to work
through my local wireless network so that I don't have to connect my
laptop to an additional device.
Thank you.

Hi there,

I guess it depends on your budjet but there are systems available. 
Have a look at http://www.ramelectronics.net/html/wireless-vga.html
for the product that I think suits your needs.

Cheers.

Am really looking for a solution that works with the wifi in the
laptop, so that I don't have to attached another device to it. But
thank you.

http://www.cdw.com/shop/products/default.aspx?EDC=372666

http://www.cdw.com/shop/products/default.aspx?EDC=834549

I have the Aitech and it's GARBAGE!

bschonec - thanks for posting these. These devices still seem to
require that I wire-connect my laptop to a transmitting device, i.e.
it does not seem to work with the laptop's built-in wifi capability.
I'm looking for something that will allow me to sit in front of the TV
with the laptop before me, with no other devices attached, and seeing
the TV act as the laptop's screen...

May not be possible...

Upon further reflection, I've decided to circumvent this problem by
hooking up a separate, dedicated laptop to the TV screen and getting a
wireless keyboard to operate it.