Comic Natalie is that Keroro Gunsou, aka Sergeant Frog, is the latest big anime franchise to attain the approval of the Japanese post office and get made into stamps. This places the goofy alien-frogs-try-to-take-over-the-world tale into the same lofty category as Naruto, Ge Ge Ge no Kitarou, and Case Closed, among many others.
Hmm, I wonder what anime they'll make stamps of next? I also wonder if the Japanese post office might try to get in on the tween vampire romance craze by making some Vampire Knight stamps. I, for one, want Gurren Lagann stamps.