Ok ok I don’t have one yet but I’m planning on one, used one last week and I have to say I’m very impressed with it, now I just need to get my hands on phone…I’ve already sold my iPod to fund it 
I guess everyone is familiar with the Mac & PC Apple Mac adverts that Apple have been running the past few years, well Apple have started using flash based adverts on some sites that are just very well thought out.
Here’s the latest one…pure genius 
EDIT
and here’s a video of it
http://www.tesco.ie/csr/index.html#2
After this thread on boards, I went in search of this policy and sure enough its on Tesco’s website, its worth keeping this in mind next time you goto tesco’s
No Quibble Policy
Our “No Quibble Policy” is our way of showing customers that we always charge the right prices in our stores. It states that: “in the unlikely event of you being charged a price at the checkouts that is higher that the price mounted on the display, we will give you that item absolutely free and without quibble”