If you aren't already an avid reader of Scott Guthrie's Blog, you should change that -- he has been posting almost every day for the past 2 months (kinda like the rain in Seattle) and has nothing but gems on there.  One that particularly caught my eye is a solid to-do list Atlas sample based on the brand new december CTP: http://weblogs.asp.net/scottgu/archive/2005/12/26/433997.aspx  -- It is a must read for anyone who as at all interested in Atlas or AJAX -- with hardly any code at all he accomplishes some pretty great stuf.