I went looking for those online, the reviews are good; they seem to vary in cost between 11 and 15$ for a sheet that is under a square foot . More expensive than real tile but you bypass the mess and the expense of labor.
It looks really good on their pictures.

Here is a link that might be useful: self stick tile

I love the idea they can be changed out. I,ll check out the link. I havent found a pattern I just have too have yet but its sure fun looking.

I saw these on some HGTV show, and they seem like a really good idea, especially for those of us who like to change things up occasionally.

Link to review below and here:
http://www.prettyhandygirl.com/2012/01/smart-tiles-installation-and-product-review.html
http://pocketfulofjoules.com/2012/05/04/kitchen-changes-part-2/

I wonder if I could use them to stick over dated accent tiles.

Here is a link that might be useful: smarttile