I completely agree with Anne's suggestion. In fact, I was thinking of asking the same question!
It appears that many people do in fact chase club badges, as evident by the list of contributions people make. A lot of people stop making contributions as soon as they hit 100 or 1000. I think having a badge at 500 would increase participation, as it would give folks an intermediate goal between 100 and 1000. I know this would motivate me. (Yes, I really am that easily persuaded into action. )
A badge at the 5000 level would be great as well. I don't think it would be awarded very often, but there clearly are a few people who achieve this level, and they should receive recognition for it.
(PS, if there is a need to create badges, I know my way around Photoshop, and would be happy to create any that might be needed.)