Portraits and computer display

I will be doing bunch of portriats soon. I have a 20D camera. Is there any way I can hook this camera to a computer and see the pictures on the computer screen on the fly? What software would you use for this kind of setup at the location? What kind of cables do I need to get? Any input will be appreciated.

C1pro (don't know about the LE version) will do this, as well as Eos Utility.
Obviously, since it's a SLR, the image will only get on the screen after you have taken the picture...
Do a search for 'tethered shooting'

Try
http://www.breezesys.c​om/DSLRRemotePro/index​.htm
I've used their p&s version and it works very well.

I do believe your 20D should have come with the standard Canon software. There is a program within this software to do remote shooting. Read your user's manual for details.

The software included with the 20D is called 'EOS Capture'.

Thank you all for the valuable info. What are the cables that I need to have to hook up the camera with computer? or the standard USB cable is good enough?
Thanks

The standard software will be able to control most of the camera funcitonality, and it connects via the standard USB cable (USB > Mini USB). DSRRemote Plus adds a few more functions (like 11-stop bracketing), but is basically the same deal as the one that Canon packages with their cameras.