LJ comm livelongnmarry is running a charity auction from July 1-15 via LiveJournal. The auction items are donated by community members and include many fannish and crafty items, as well as some interesting services (learn Mayan hieroglyphs!). As to the cause, I will quote the comm:
The auction will raise money for the fight against the California initiative which will legally destroy existing same-sex marriages and ban any further ones. If the initiative passes, it will write discrimination into the state constitution, annul existing marriages, and make Mr. Sulu cry.
You can read more about the auction format and rules at the community’s info page. The info site also gives details on the organizations preferred to benefit from the auction, although the gist is that you can donate to ANY coalition fighting for marriage equality.
I should also note that I learned about this auction from an LJ friend, so feel free to take a special look at her baked goods offering. 🙂