From our reader:

The 1929 Georgian Revival mansion @ 3450 Washington is apparently set to be the site of the 2010 Designer Showcase.

Posthumously attributed to Architect Willis Polk (1867-1924) the 8,000+ sq.ft. Presidio Heights home was purchased by Peter Sperling in 2001 for a purported $18 million (story and other high end real estate gossip here), and has been on and off the market ever since.
Still listed on the Joel Goodrich Coldwell Banker website “price upon request”.

So let’s see, not on MLS, but still “available”? Sounds like something for PocketListings.net. Thanks for the tip and thanks for reading!