Of course reading my way through the lists and descriptions of his work made me hungry to watch some of it ... sadly, very little is available over here (I'm lucky enough to own one CD of his stand-up, with another currently in shipment from Chapters/Indigo, plus one DVD with him in a starring role and one where he has a brief bit part. On the happy side, fans have made sure that he's all over YouTube, including episodes from the tv series that's considered one of the highlights of his career: "Up Pompeii".
For those not familiar with him, Howerd's screen trademark was playing characters who were aware of the fourth wall and who would talk to the camera/audience as easily as they interacted with fellow characters ... while other performers have used this same technique, it's always been very obvious and none, IMHO, not even George Burns who claimed to have pioneered this trick for live tv in the 50s, did it as seamlessly and naturally as Howerd. Couple this with his ability to make ancient music hall and/or downright corny gags seem new every time he performed them, his seeming to continually lose his place, blow his lines, adlib and be outraged (every bit of which was carefully scripted), and his magical talent for getting away with coyly saying things that would have been censored if they'd come out anybody else's mouth, and the result is the perfect lowbrow, sexual-innuendo-loaded, comedy performance.
Have a peek, and several titters, at the first episode of "Up Pompeii", "Vestal Virgins" (I'm off to see what other episodes I can find):
Special note: Part 2 contains a rare unscripted adlib ... Howerd blows a line for real and covers by telling the audience that he's had "a lot to learn, you know")