My wife blogged about a recent announcement by Japan Post (sorry both links in Japanese and google's translation is odd). The idea is that you fill in a form and submit a suitable image or series of images and they then turn it into standard rate postage stamps and send you ten of them on a decorative sheet. The cost is ¥1200 for the 10 stamps which have a face value of ¥80 each so you are paying 50% more for the privilege of personalizing them. I believe you can order a lot of sheets if you want and if you order over 1000 then you can also customize the decorative sheet too and have ten different images in the sheet (such as in this image below)
This sounds like a truly excellent idea and I wonder whether any other post offices around the world are going to do the same thing. I can see this being a winner for all sorts of announcements as well being a great advertising gimmick.