To be honest, I never pegged those cookie-baking elves as straight, but an outfit in Santa Barbara is selling "Wooden Tree Houses Straight from Nature, Made by Elves." They're made from wood gathered from orchards and managed forests using sustainable harvesting techniques, and you can get either a built treehouse or a reconfigurable one. Optional accessories include suites of log-like furniture that wouldn't look out of place in a media mogul's Sun Valley ski lodge, Branch Family dolls that look like little garden gnomes--and a set of fairies [guess the lawyers from Keebler got after'em for the "elves" thing.]
Equally awesome and a fraction of the price: Tree Blocks, stackable, nicely finished--with or without bark--building blocks in the natural shapes of the branches they were cut from, which look they'd be perfect for countering the rigid conformism that comes from playing with regular square blocks (which shall hereafter be known as environment-pillaging neo-capitalist stooge's blocks.)
Tree Houses, $139-159 and Tree Blocks, $27-47 [treeblocks.com via treehugger]