One of the best things about your SmartBoard is sharing! You often don't have to come up with your own SmartBoard lessons - you can "borrow" them from other teachers using resources like SmartExchange. That's what it is set up for - why spend your time reinventing the wheel when other teachers are teaching the same material across the country?
The teachers in Cobb County, GA have set up some great SmartBoard lessons that they are sharing via the internet. They call them the "Math RAP files for SmartBoard". Each month they have included timely math review lessons that are fun and challenging. They include activities for the SmartBoard to include during your morning meeting time or during math review. These lessons are designed for grades 1 through 5 to match the curriculum. Click on the picture on the left and download the lessons directly from their site. Customize them for use in your classroom.