I'm going to vote for the online shopping option. I have the choice of Sainsburys, Tesco, or Waitrose online shopping -- all deliver to my area. I've used Sainsburys so far, and really like it! Especially the "Recipes" section -- find a recipe you like, click, and the ingredients are put into your trolley, along with a note to make sure you don't already have those things in your trolley. Talk about convenient! I also, like someone else mentioned, like the fact that the price totals up automatically as you shop. Makes it easier to keep track of spending.
Stephanie