Smartboard Friendly Elapsed Time Clocks
This website provides great student whiteboard activities for elapsed time. There are two clocks that are completely changeable so that you can ask students what the elapsed time is. I use the dice frequently because it provides completely random times. You can hide one clock and then give how many hours before or after that specific time and now your students have to either draw the time they calculate it to be and then unhide the clock so students can verify their calculations.