Planning poker is an interesting approach to make estimations. If you interested in it but didn’t have a chance to try it yourself, the following link will be extremely usefull http://planningpoker.com/.
It’s free and straightforward online tool to make estimations using Planning Poker approach. So now you don’t need to search physical cards to test Planning Poker approach. All that you need is just one moderator registered at planningpoker.com. Other developers could just specify their names.