S7,535 sq. ft. 7 bd/6.5 ba. 3-car gar. Wet bar. Wine cellar. MUST SELL NOW. Okay, that last bit isn't part of the listing for Tom Perkins's palatial home in Belvedere, across the Golden Gate from San Francisco. But the fact that Perkins wants to sell his house, in this real-estate market, is disturbing. He is one of the founders of Kleiner Perkins Caufield & Byers, and is fabulously wealthy. He has already started hawking his $187 million megayacht, the Maltese Falcon. What this looks like: Perkins is liquidating his worldly possessions. Let's assume he's not doing this because of financial straits. The only alternative conclusion: Perkins thinks he should sell now, before things get much, much worse.