This spreadsheet of grocery prices (http://spreadsheets.google.com/ccc?key=peDUm_sm3BL45sEllHy5ofw&hl=en) will make price comparison a cakewalk.
It is still a work in progress. You can help by saving your grocery receipts and inputting the prices.
Anyone who would like to contribute/edit, please send me any email address you would like to receive an invite at.
Feel free to add more stores... I'm currently collecting data on Sam's Club, Market Basket, Walmart and Stop and Shop.
Cool idea :)
This is great. I was hoping someone would do something like this.