You can do this:
<ScrollViewer
HorizontalScrollBarVisibility="Auto"
HorizontalScrollMode="Auto"
VerticalScrollBarVisibility="Disabled"
VerticalScrollMode="Disabled"
ZoomMode="Disabled">
<ItemsControl ItemsSource="...">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<callistoControls:WrapPanel Orientation="Vertical" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button />
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</ScrollViewer>
Best of luck.