I was playing an MMO called Navyfield a couple of years ago. In its forums, the suggestion board has a "recommandation" button on every post. When a user click on the button, the poster gets 1 "point" and the total number of the recommandations a post got is shown on the board view. Go to
http://www.navyfield.com/board/list.asp?Sort=D08 to see the board. After you scaned a few pages, you can see only a few can get to the hundreds and the sticky "Ultimate CV wish list" has over a thousand. This recommandation system can easily distinguish the REAL good ideas from the bad ones. Implementing something like this in the Card Ideas and Suggestions boards would be great.