You can also save petrol, traffic and energy for something else. A new portal has come up - www.greenytails.com - that delivers the Grocery for you at your door step. The delivery is done for free as long as you order for a minimum of Rs. 300.
Greeny tails also promises to supply you with tonnes of promotion codes/coupons if you send them an email at firstname.lastname@example.org, with subject line bearing "Request for promotion codes". The portal seems to be promising but still lots of work to be done for sure.