Gates' house, viewed from Lake Washington. Flickr Photo, TikTik

The latest sign of the economic recovery: Bill Gates' house.

Each fall as part of Microsoft's charitable giving campaign, people at the company donate products, services and experiences for their fellow employees to bid on. The item that typically fetches the highest bid is a tour of Gates' Lake Washington home for the winner and a small group of friends, guided by Gates, with appetizers at the end.

Last year, in the middle of the economic meltdown, the winning bid was $8,600. This year, with things starting to rebound, the bidding rose to $35,000. No word on who was willing to pay that much, but presumably it wasn't a junior tester.

The factoid was mentioned as an aside yesterday afternoon during a presentation by Microsoft CIO Tony Scott at the Society for Information Management's national SIMposium convention in Seattle. Scott showed the audience Microsoft's internal application that runs the auction for the giving campaign, which has been rebuilt on the company's soon-to-be-released Azure cloud-computing platform.

"Can you imagine?" Scott said of the winning bid for the Gates tour. "We're encouraging Bill to donate that item again next year."

Of course, the philanthropic element makes it a little dangerous to derive real-world valuations from the bids. For example, the bidding this year for the "world's best bologna sandwich" hit $500 this year, up from $250 for the same item last year. Microsoft matches the donations, by the way, so the overall value of $1,000 might just make it the world's most expensive bologna sandwich, as well.

For the record, the sandwich does come with pickles and chips. Maybe Gates could throw those in next year to boost the value of his house tour.

Related: Bill Gates' House on the TechFlash Geek's Guide to Seattle