Well, it's on a hill, but it sure ain't a cabin. Instead, Bebo cofounding couple Michael Birch and Xochi Birch have purchased a $29 million manse in Pacific heights on the corner of Broadway and Broderick. It looks like the Birches purchased the property from one William Mathes, a managing partner at Behrman Capital. Mathes originally purchased the lot for a mere $3.25 million back in 1998.