There are currently 68 items up for auction, the most popular being NASCAR driver Jimmie Johnson's tribute helmet; which he's currently wearing in the 2011 Sprint Cup Chase. The helmet's visor features a tribute to Wheldon. The current bid is $20,000, and the winner will actually have to wait until Jimmy's done with the helmet at the end of the Chase to collect it.
The auctions, running on eBay as we speak, will send 100% of their proceeds to the Dan Wheldon Family Trust Fund. You can get more information and make a donation on the Dan Wheldon Memorial site, or head straight for the auctions and place your bid.