From Wired.com :
"02:00 AM Aug. 11, 2004 PT
Every year, the U.S. Postal Service receives 40,000 submissions for new stamp images and releases about 35 of them. But now, thanks to PhotoStamps, a trial service from Stamps.com formally announced Tuesday, the number of new stamps hitting envelopes nationwide could become nearly infinite.
PhotoStamps allows anyone to design their own image and emblazon a stamp with it. Thus, be prepared to see a wave of stamps with babies, cats, weddings and other personalized images and logos arriving in a mailbox near you."