ItemsPanelTemplate with Horizontal Orientation

ControlTemplate, ContentPresenter, & TemplateBinding

See example for these at bottom of http://msdn.microsoft.com/en-us/library/system.windows.controls.contentpresenter(v=vs.95).aspx

Storyboards

http://www.silverlightbuzz.com/2009/10/12/animating-with-storyboards-in-blend/

itemscontrol itemspresenter listbox

http://stackoverflow.com/questions/3723893/itemscontrol-itemspanel-and-itemspresenter-silverlight-xaml
Note, ex on itemspanel "Basically, the ItemPresenter (specified in the Template) will be replaced with whatever is specified in the ItemsPanelTemplate." -mmmmmm