They discussed his website on a recent BBC documentary (http://www.bbc.co.uk/programmes/b00nn7vs) at 00:32:37 (transcribed below). The whole documentary is certainly worth watching.

  Davis:
  "Berkshire Hathaway is a massive company which feels like a family firm.
  All the usual corporate vanities are absent and not a cent is wasted. Take a
  look at the Berkshire Hathaway website here. To call it low key would be to put it
  kindly, it looks though it's from about 1994, no-frills. All the financial data
  is here but they haven't even got around to even uploading a photo. And
  that's all very much Warren Buffets style - why waste money on a designer.
  Buffet insists his website does the job."

  Buffet:
  "I think it's what we are, I mean, it's factual."

  Davis:
  "You could put a little picture of something on there perhaps, or."

  Buffet:
  "I want people to get facts about Berkshire and, you know, I don't
  really think it makes any difference what I look like."

  ---

  Davis:
  "Buffets idiosyncratic style is not just charming, it's a financial asset,
  it saves time and money..."