The US Postal Service released a souvenir sheet of Edwin Hubble postage stamps on the 10th anniversary of HST launch, April 10, 2000. The occasion was marked by a ceremony at Goddard Space Flight Center (read the USPS press release here). The Ring Nebula image selected for one of the stamps was the first new HST image to be obtained under the Hubble Heritage Program, and I had the privilege of being Principal Investigator for this observation.
You can read more about the science behind the stamps here.
And if you want to buy some, go to stampsonline.com.