This contest may appeal to greeting card writers. Minted.com is hosting a contest for wedding invitations, You can view the complete guidelines and download the submission kit on the contest web page, but it's an open contest with big prizes and no entry fee. The top prizes awarded will be $1500, $750, and $500, along with the fourth- through thirtieth-place winners receiving $200 each.
There is definitely a lot of money-making potential here. In addition to the top 30 cash prizes, additional special prizes will be awarded, including a $250 Newbie Award among many others. The deadline to have your submission in by is November 22nd.