Coupons on your cell phones

one of the things I always forget to take to the store with me is those damm coupons that looked like such a great deal...solution for us mobile geeks? we have our cell phone with us all the time.. (ok maybe only some of us do) - cellfire is a free coupon service that sends coupons to your cell phone... it only has a limitted amount of companies listed..but its still a pretty cool idea..how to make it cooler? gsm triangulation for the application to know my location and send me coupons based on that! (since gps embedded cellphones arent wide avail yet) .. i really wished there were more (any at this point) services using gsm triangulation...