Thanks for reply, I am already started research work, "comparison shopping " and "comparison shopping cart" is big difference. I am not asking hole stuf. I am asking just related article and notes.
...

Thanks, I need specfic to "Comparison Shopping Concept" not general difference between shopping cart comparison.

Thanks
VVN

I Need to build comparison shopping site like http://www.nextag.com /
and http://www.gosale.com/

Any notes or open source code.

Thanks