Why spend valuable preparation time reinventing the wheel when there are sites offering ready made resources for the interactive whiteboard? The files may not be exactly what you were looking for, but the downloaded resource can be used as a starting point and adapted to the needs of the lesson. The National Whiteboard Network from the primary strategy is probably the best starting point. It contains Smart board, Promethean board and PowerPoint files on Literacy, Numeracy and foundation subject units of work.
There are more resources for Smart boards at the Smart Education site.
Promethean have recently launched a new site called Promethean Planet to enable user to share resources. The Lighthouse for Education (North East Linconshire) also contains Promethean Flipcharts.
The Birmingham Grid for Learning have interactive resources that can be used on all types of boards.

National Whiteboard Network