Thanks Arnor :) As you say, nowadays we have less uses for our memory: that's why paper, pen and iPhones are for. I'm trying to use the memory palace technique to help my language learning (you know, like Icelandic ;), but it is also good to remember things like "hey I should do this by tomorrow" that appear when you are in the shower, or shaving. When you usually have no gadget around (waterproof iPhone, anyone?).

I usually carry many gadgets around (iPad, Ben Nanonote, iPod Touch, pen and paper are usually always with me) and as such, it is far easier to write down important stuff. But when I don't have them available, let's visit some standard palace and put the stuff there.

As for memory supermarket... If you always go to the same supermarket, you can use it as a palace, in the appropriate places you just put some kind of reminder, like a lemon avalanche or the big Bread Man.