By default, the DataList control displays a single column. However, you can specify any number of columns. Within the columns, you can specify how the items are ordered: vertically (the default) or horizontally. Vertical layout in three columns results in a layout such as the following:
A D G B E H C F
Horizontal layout for the same items results in the following layout:
A B C D E F G H
To specify column count and ordering:
[Visual Basic]
DataGrid1.RepeatDirection = RepeatDirection.Horizontal
Introduction to the DataList Web Control | Specifying List Format