William Hanna, whose wit and character sense informed cartoons from Tom & Jerry to Scooby Doo, died in Hollywood at the age of 90.  Hanna teamed with Joseph Barbera at the old MGM studio in the 1930s where they created the wonderful series of Oscar-winning Tom & Jerry cartoons, which told elaborate gag-filled stories almost entirely without dialogue.  Ironically, when MGM axed its animation unit in 1957, Hanna and Barbera switched to television where they pioneered a limited animation style that relied to a great extent on verbal wit and clever catchphrases ('Yabba-dabba-doo').  Before they retired, Hanna/Barbera produced over 3,000 half hour animated television shows featuring such characters as Huckleberry Hound, Yogi Bear, the Jetsons, Atom Ant, Quick Draw McGraw, Jonny Quest, Top Cat, Scooby-Doo, Pixie and Dixie, and Magilla Gorilla.  With the advent of the DVD format, the television cartoons of the late twentieth Century have become hot once again (see 'There's Gold in Them Thar Old Cartoons').  In addition to the HB material already available, this summer Warner Brothers Home Video is releasing a compilation DVD entitled Cartoon Crackups that should be a fitting tribute to Hanna/Barbera.