UBERCART - How to Save Abandoned Carts Without an Email Address ? How to get customer Email early in Checkout process ?

UBERCART - How to Save Abandoned Carts Without an Email Address ? How to get customer Email early in Checkout process ?

Interesting post:

http://www.getelastic.com/how-to-save-abandoned-carts-without-an-email-a...

Do you have any idea about how to open a popup when customers leave your shop and how to add an Email address request box before checkkout ?

Thanks.