I shop at a wide variety of grocery stores, around the country. Most grocery store chains offer better prices if you check out using a 'membership card' of some sort. Unfortunately, most chains are pretty regional, and I'm really not interested in signing up with all 20 of the grocery stores I shop at in any given year... to say nothing of the privacy implications of allowing the grocery chains to track my every purchase.
How can I get access to these better prices without signing up for a card myself?