A number of U.S. celebrities have been spotted toting Hello Kitty paraphernalia in the past year or so, leaving officials of Sanrio Co., the maker of the long-selling character, scratching their heads.

Mariah Carey has been seen carrying a Hello Kitty boom box, Cameron Diaz has a Hello Kitty necklace and figure-skater Michelle Kwan has been photographed with a Hello Kitty purse dangling from her shoulder.

Longtime Hello Kitty devotee Lisa Loeb even put the mouthless feline on the cover of her latest album, aptly titled "Hello Lisa." And New York fashion design duo Heatherette has incorporated Hello Kitty motifs into its line of punk-inspired couture.