http://mixsandbox.com/ - Check back here to see some of the great things MIX06 attendees will have built using technology they learned @ MIX 06. Sandbox in the Sky will be available for 6 months after MIX06 ends.
https://content.mix06.com/content/sessions.aspx - you can download some of the presentations (slide-decks & sandbox material) from MIX06 here
There are also some more useful resources and news from MIX06 here @ http://thespoke.net/forums/947739/ShowPost.aspx