From their website:

Wish Upon a Wedding grants wedding and civil union ceremonies for adults with terminal illnesses, at destinations across the United States. With our headquarters located in the San Francisco Bay Area, and a nationwide network of volunteers and supporters, we serve those in the greatest need around the country. We receive no state or federal funding, relying instead on the generosity of our supporters to fulfill Wish requests.  Wish Upon a Wedding was founded in San Francisco, CA, in January of 2010. America’s ONLY wedding wish granting organization, WUW will begin accepting applications for wishes on February 14, 2010. WUW anticipates granting dozens of wishes per year, with the possibility of that number turning into hundreds.

To apply or get involved visit their website:  http://wishuponawedding.org/