Google webmaster tools

Have you looked at the articles here? http://wiki.earlyimpact.com/productcart/seo

Hi, Google webmaster Tools doesn't seem to be a specific piece of software, more a collection. Can you explain exactly what you want to add - perhaps a URL to the Google page about it?

ProductCart supports :
 - Generating a Google Base File
 - Google Analytics
 - Google Website Optimizer
 - Google Checkout
 

I think the original question might relate to 'verifiying' your site with Google so it knows you are the owner. There are two ways, one is to put a meta tag on your pages, the other is to upload an html file to your store.
Go for the second one by uploading the file that they tell you to your main website.

For example they will ask you to upload google5e8e31232a387.html to www.yourdomain.com so that they can view it at www.yourdomain.com/google5e8e31232a387.html

The file can be empty. What i tend to do is open notepad, save an empty document as that name on my desktop and then use FTP to upload it. Once you have done that, go back to Google webmaster tools and click on Verify. It should then check the file is there and let you get on with things.

Google webmaster tools aren't something specific that integrate with productcart as such but productcart does have some useful extras that make using the tools a lot easier. Googles has a number of tools and you can choose the ones you want.