Check out We R Memory Keepers at http://www.weronthenet.com/Operation_Write_Home. They sponsored a card drive for OWH last summer and they are doing it again this year. They are giving weekly prizes, getting stores to collect cards, and doing Facebook updates. Operation We R Grateful, The Contest, runs June 1, 2012 through July 31, 2012. So, get your own craft supplies out and make a few cards. See the site above for mailing address and entry forms.
Here's some info as posted on their site.